Not everyone streams music. I don't. I sometime stream sports commentaries but only if they are not on broadcast radio. Listen to lots of music and music programmes but all downloaded ahead of time.
As far as the OP goes I mostly use Smart Audiobook Player but also VLC. Samsung Player is a bit Mickey Mouse and lacking in functionality.
Do you have any evidence that the "vast majority" do stream and exclusively stream?
I have discussed this before in another place and the only evidence proffered was an industry study that was only about new music and did not mention exclusive mode of listening.
I would accept that a lot of people stream for much of the time and even that most people stream for some of the time but that is as far as it goes.
Everyone streams music now, pre installing a music app in 2021 is almost totally redundant.
That's also what I use. I got a Pro licence over 6 years ago when it was on sale, and I've used it for all of my Android devices since then.PowerAmp for the win!
Very good pointFWIW, I've never felt comfortable relying on streaming for music. If you lose wifi, or have a poor cell signal, you've lost your music. I'd much rather have control of my music not the streaming service.