i use a feature phone / dumbphone that has an sd card slot. load up the sd card with music, and the player is super simple and works great for me. bluetooth earbuds work too, but the rechargable battery of mine died after owning them just a few months longer than the warranty lasted, so i'm back to using wired earbuds (with a usb-c to 3.5mm adapter, do NOT buy the cheap shit from temu, get one that actually sounds decent).
the phone was like $50, and a prepaid sim card inside it makes it so i can use it as cheap backup texting/calling device too when i want to disconnect from all the bullshit the smartphone comes with for a while (still trying to get fully rid of smartphones but it's very hard these days)
the way i understand it, it's mainly about user accounts. people will not make a new account for every website they go to, that's the reason these centralized platforms are so dominant. The idea with forgejo (as i see it) is to allow people to register on one forgejo instance, and use that login to contribute to any other forgejo instance as well without first having to sign up.
as far as i know, git doesn't really have a concept of user accounts. yes there's signing commits, but the actual access to the repo has to be handled outside of git itself.
Now, federating forgejo and allowing other instances to contribute is only one step removed to simply opening it up to the entire internet. but i imagine instance owners will figure out ways to prevent spam and abuse quick enough.