A YouTube music subscription also gets you YouTube Premium. Granted, you might just use ad blockers for the primary benefit of Premium, but if you're going to pay for one thing you can technically get for free, that same purchase might as well get you something else that's free.
I'm on Android and I use Apple Music. It's very good and well worth it. This is coming from someone who still despises Apple, but my partner used Apple Music and we got a family plan.
My solution is Newpipe. It is an alternative YouTube front end you can download via F-Droid that lets you access YouTube, peer tune and Bandcamp without ads. It isn't as good as YouTube music especially since you don't actually have an account, but you can still make local playlists and download music.
I switched to Tidal about a year ago and have been pretty happy with it. Better audio quality, they compensate musicians better, and I prefer the UI. They both have 80m+ songs.