Yeah, the thing with phones is they're used every single day, and see a lot more wear and tear than say, a Kindle or a laptop. Not everyone wants to fork out for an OtterBox or some other ultra tanky case.
I try and go four years between updates, but for my Pixel 4 that meant a warranty replacement on year two due to a charging defect, and buying another used Pixel 4 off a coworker three months ago when mine got water damaged. The replacement just shuts itself off randomly multiple times a day, and that's fine for a couple months but I'm really looking forward to upgrading to the Pixel 8.
We probably shouldn't treat phones like leading cars, upgrading every year because something shiny and new came out, but upgrading regularly just due to wear and tear makes a lot of sense.
My last upgrade was from an s7 to an s21. I finally had the money to buy it outright/unlocked, and jumped on it when I saw the model had a plastic back.
Only downside is that AT&T won't let me use visual voicemail because I didn't buy it with their bloatware. I know it can be fixed, and I've tried a few things, but I just gave up in the end because it was too much hassle.
It'll probably be a long while before I upgrade again, but the fairphone does have my attention now. I'm already used to not having visual voicemail, so I'm sure I can adapt more to have the Samsung bloatware gone too. But I probably have another 3 to 4 years left with my s21 for now