Rhythmbox with the Alternative Toolbar (created by me!) has been a staple of our distro for a very long time. It is maintained as a package by Canonical and is in the main repo.
There are no plans for Rhythmbox that I have found that state a GTK4 uplift.
Development is painfully slow.
So is there an alternative good looking music player that is well maintained in the repo?
That’s an open question to you all.
I’m currently thinking about swapping to lollypop - it is actively packaged by Debian. Development is on-going with regular minor point releases every few months. It is a good looking player - with development under the GNOME umbrella Releases · World / lollypop · GitLab