So I'm browsing around the internet as I do and figure a quick google search on best Old Phone and the top result I got was from ZDNet - an article written in April of 2021 talking about how old phones does not equate to bad.

This of course took my attention as a (new) collector of relic phones that I often use (not as main device, secondary carry) but the suggestions for OLD phones that are still good was fairly laughable...

OnePlus 7T Pro 5G McLaren
OnePlus 7T
Samsung Galaxy Note 10 Plus
Samsung Galaxy S20
Apple iPhone 11 Pro and Pro Max

The phones being suggested (above) are really good phones, fantastic in many respects but old enough to be put under the question of is it good? Not even close. However not everybody has the same thoughts on devices I do so your list may be entirely not in line with my own, this is fine! You may also think that the devices above are perfectly fine to suggest as "old but still good" this is also fine!

My personal daily phone is an iPhone X - she's showing her age and the battery life is none existent - camera is still decent up unless you want to shoot at night, in short the phone is fine but I've had the device since it first came out and do plan to replace her around the middle of this year.

My take on any device being still thought of as old but still usable always comes into the same line of thinking - if it's still supported by the manufacturer (receives software updates) then it's still an absolutely usable device.

The Fruit Example

Exceptions to this list do exist of course but if we look at Apple and what they supported with iOS 15

iPhone 13, iPhone 13 mini, iPhone 13 Pro and iPhone 13 Pro Max
iPhone 12, iPhone 12 mini, iPhone 12 Pro and iPhone 12 Pro Max
iPhone 11, iPhone 11 Pro and iPhone 11 Pro Max
iPhone XS and iPhone XS Max
iPhone XR
iPhone X
iPhone 8 and iPhone 8 Plus
iPhone 7 and iPhone 7 Plus
iPhone 6S, iPhone 6S Plus
iPhone SE (1st and 2nd generation)

That's a LOT of possible options that are still currently supported but we know iOS 16 is probably on it's way and it is expected but not confirmed that the below devices will be axed (no longer supported)

iPhone 6S, iPhone 6S Plus
iPhone SE (1st Gen)

We don't obviously know if this is true it could be more devices left "unsupported" or none at all, last year it was speculated by the usual reliable leakers that the 6s would be dropped and alas, it wasn't so take that for what it's worth. Also do keep in mind that unsupported in this scenario means that Apply won't be pushing out a major update (iOS 15 -> iOS 16) but minor updates (iOS 15.0.1 -> 15.0.2) will still be issued.

So in terms of the suggestions from ZDNet you should look at an iPhone 11 or above and for iOS honestly look at anything with at least 2 years of support so 7 or above - again we are working on "old still good" but be careful when picking up a second hand phone (this is true of ANY modern device android or iOS) mostly because battery life will likely SUCK and you will not get anything close to original release specs - unless you replace the battery which isn't easy (but not impossible) on any modern devices due to them usually being glued down.

Apple Old but still good (and cheap) worth using

So from the original iOS supported devices we can remove what we think won't be supported and devices I happen to think are not worth it for a daily driver.

iPhone 11, iPhone 11 Pro and iPhone 11 Pro Max
iPhone XS and iPhone XS Max
iPhone X
iPhone 8 and iPhone 8 Plus
iPhone 7 and iPhone 7 Plus
iPhone SE (2nd generation)

So the 13 and 12 were removed as they are still fairly new and expensive, the XR because it was and is trash - the SE makes it look like bad value, the 6 and SE Gen 1 because they will likely be dropped.

Droid Rising

Apple is not the only game in town and I know this so please put down the pitchfork and don't hurt me, my current secondary device for access to android specific stuff is a Nexus 5 - it's a little sluggish but at present is the most reliable android device in my phone collection

Android unlikely iOS is a little less straight forward in terms of what is and what is not still supported not because it's all that hard to find what's supported by a manufacturer but because you have SO many manufacturers putting out device updates and offering a variance of support options but I've done my best to get a good list of what's supported by who on the latest version Android 12 update

Google

Pixel 6, Pixel 6 Pro
Pixel 5, Pixel 5a 5G
Pixel 4, Pixel 4 XL, Pixel 4a, Pixel 4a 5G
Pixel 3, Pixel 3 XL, Pixel 3a, Pixel 3a XL

So from the Google Pixel specific of things it's fairly simple, they dropped support for the 2x series based on what the linked article suggests and have an a yearly release cycle so if we suggest that the Pixel 3 will be dropped next year and we base our projections on what costs how much we remove the latest due to cost and the last due to probability of support being a year which leaves us with

Google Pixels Old but still good (and cheap) worth using

Pixel 5, Pixel 5a 5G
Pixel 4, Pixel 4 XL, Pixel 4a, Pixel 4a 5G

The Pixel 5a 5G is still sold by Google themselves but a new price is $449 which is still on the ouch side of things, while the Pixel 4a is sold by Google for $349 - both of these are brand new prices and if we go by brand new then the 4a is probably the best option but I left the Pixel 5 series on the buy list as it can be picked up fairly cheap on places like eBay but of course YMMV.

If you're just looking for the Pixel experience or just a solid camera for cheap then the 5a and 4a will suit most just fine.

(I looked but could not find an actual post from Google saying hey we will support or we do support the Pixel X to the Nth so I had to take what's on 9to5Google as gospel)

Samsung

The Foldables / Z Series

Galaxy Z Fold 3, 2, original
Galaxy Z Flip 3, Galaxy Z Flip 5G, Galaxy Z Flip

The S Series

Galaxy S21, Galaxy S21+, Galaxy S21 Ultra
Galaxy S20, Galaxy S20+, Galaxy S20 Ultra, Galaxy S20 FE
Galaxy S10, Galaxy S10e, Galaxy S10+, Galaxy S10 5G

The Note Series

Galaxy Note 20, Galaxy Note 20 Ultra
Galaxy Note 10, Galaxy Note 10+, Galaxy Note 10 5G

The A Series

Galaxy A82 5G
Galaxy A72
Galaxy A52, Galaxy A52 5G, Galaxy A52s 5G
Galaxy A42 5G
Galaxy A32 5G
Galaxy A71 5G
Galaxy A51 5G, Galaxy A51
Galaxy A21
Galaxy A12
Galaxy A02s
Galaxy A01
Galaxy A11

The M Series

Galaxy M42 5G
Galaxy M12
Galaxy M62
Galaxy M01
Galaxy M02s, Galaxy M02
Galaxy M21, Galaxy M21s
Galaxy M22
Galaxy M31, Galaxy M31 Prime Edition
Galaxy M32, Galaxy M32 5G
Galaxy M51
Galaxy M31s
Galaxy M52 5G

The F Series

Galaxy F41
Galaxy F42 5G
Galaxy F62
Galaxy F02s
Galaxy F12
Galaxy F22

The X Cover Series

Galaxy Xcover Pro
Galaxy Xcover 5

Samsung Old but still good (and cheap) worth using

The flagships of Samsung are easy to cut down on for one reason or another, in short no folds or flips, while nice and interesting - they cost money, lots of moneys!

Giphy - Make It Rain Money GIF by SpongeBob SquarePants

I'm sure someone will point out that the original Fold can be picked up fairly cheap, but would you REALLY want to spend precious money (remember in this concept we are on a budget!) on a not quite as reliable (screen central cracks) as it's later brothers.. so no folds, no flips.

It's a little less obvious with the S series and below but anything on it's last guaranteed from manufacturer update is out and anything that's the latest is also gone.

The S Series

Galaxy S10, Galaxy S10e, Galaxy S10+, Galaxy S10 5G

The Note Series

Galaxy Note 10, Galaxy Note 10+

The A Series

Galaxy A32 5G
Galaxy A71 5G
Galaxy A51
Galaxy A21
Galaxy A12
Galaxy A02s

The M Series

Galaxy M42 5G
Galaxy M12
Galaxy M22
Galaxy M32, Galaxy M32 5G

The F Series

Galaxy F42 5G
Galaxy F62
Galaxy F12
Galaxy F22

The X Cover Series

Galaxy Xcover 5

On the original list of supported list I have only used the Samsung Galaxy Note 20 Ultra - but based on some googling and quick look overs it seems Samsung have a lot of devices in a good price range - the good in terms of devices is very open to debate, I hear good things about the A series devices but they are a little pricey for middle of the road in my opinion.

(most Samsung information above came from Samsung, Sammobile and 9to5Google and no, I had no idea they had this many devices in rotation)

At this point I'm still debating on if I add more info or debatable on what is good but old - but for now you only get Apple, Samsung and Google Pixel mostly because information from official sources isn't the best anyway if you want a specific manufacturer looked over let me know or if you want to add your own list drop a reply or link in a new post!

Finally, for the curious here is the original article