I have a Pixel 4a5G and it is still going strong with CalyxOS. In fact, they are about to release Android 15 for this device, which lost all its support from Google at 14. Using one of these open source, pro-privacy alternative OS’s is the only true way to degoogle your phone, so I would suggest buying a new or used unlocked Pixel phone. I will never go back to running on pure Google again.
I use RiMusic which is Google Music without the adds. You can get it via Fdroid with the IzzyOnDroid repos added. There is also Spotube for all platforms, also available on Fdroid. I haven’t had time to try this one out.