Consider also the missed market opportunity: my personal devices are 13yo laptop and 9yo phone. If an app isn’t compatible or makes it lag, I delete it and download a competing one. I’m not alone, and yes: I have money to spend on your app. I just don’t want/need to upgrade hardware that often.
Kudos for keeping your devices for so long, I also try to have mine last as long as it's practical, but so far i didn't manage to have them last so long. Unfortunately, you're in a minority. Most people would change their phone once the apps they're using aren't compatible with it anymore. So devs don't consider this aspect much.
