I've been daily driving Linux phones for the last 18 years and I would never switch away. Sure, at the beginning it required you to make it your hobby, but you were being rewarded for it. Sometimes when I'm looking at Android/iOS devices being used over someone's shoulder I'm quite horrified at what I see and what people consider normal these days and so glad that my phone works for me rather than anyone else.
What you can do with that phone that’s useful?
Everything I do online when I'm not in front of a PC I do on that phone. Web browsing, RSS, instant messaging, e-mail, social media, banking, navigation, public transport routing, TOTP auth, music playing, photo taking, weather checking, "smart" home stuff, conference agendas, occasionally some games or even software development (but not a lot these days - I used to program on my phone a lot when I was a teenager though). I even ran Jamulus on it to jam online during covid because it achieved better audio latency than my laptop, long before it got its Android port. Oh, and phone calling sometimes too, even though I've never been a big fan of that. Anything I need to, really.