Don't worry, you're not alone!
For my current phone (XR), I'll keep using it after Apple officially stops providing iOS updates (which looks like to be either iOS 17 or 18). The XR should still get security updates for a few more years once iOS updates stop...
The bigger issue I see is app support: looking at the apps I've got on my phone and the app store, most apps provide support for 1 or 2 prior versions of iOS (so at time of writing iOS16 is the latest version...most apps I see provide support for iOS 14 and/or iOS15).
In all likelyhood (assuming my phone doesn't break or otherwise stops functioning) I'll keep using my XR for a few more years. No desire to spend 1000 USD/EUR etc etc (heck even 500) on a new iPhone that does essentially the things my current XR does (just a bit faster)...though using USB-C to charge the phone would be convenient...
