My home phone is a Pantech Breakout (2011) running Android 2.3. It's my favorite android version, easily hackable, rootable, and it was the last truly open Android before Play Store and the like. It won't allow a Google login but I don't use it anyway. Email works, Browser works (and third party browsers work around compatibility), phone and messages works, but lately it's running super hot and won't last longer than 3 hours on a charge. Battery stats say 'time without a signal' is 100% but it's got five bars of LTE, and 4 bars of 1x, and everything works. Same issue with the same SIM on my HTC Thunderbolt as well. Must be some kind of network issue somewhere but I can't pinpoint it. It worked fine until July sometime. Now it's acting like its searching for signal but it has signal. Cell Standby accounts for over 80% of battery use no matter the apps you use.
Nothing I use a phone for requires a Google account, or any modern apps. I use the same apps and the same things I've done with a phone I've done since 2010. My needs haven't changed. Music, email, notes, calculator, SMS messaging, phone calls, that's it. I don't need any more than that.
The only thing that has changed, and requied me to upgrade to a more modern phone (Galaxy A13 5G) happened around Covid lockdown time. I got into using a few apps (Walmart, Little Caesar's, Burger King) to get food delivered and now I just am used to using those. Those apps require Android 6+ and the battery was starting to swell (again) in my Galaxy S5 so I got an A13. Should be good for the rest of my life.
My normal policies (ADB delete Play Store, Netguard disable all updates, any apps that don't depend on internet, route all requests to Play Services to 127.0.0.1, reinstall all my Android 2.3 apps, skeuo up the UI, etc) still apply.