If you need an ad blocker without root use BLock This or Blokada.
I found this but haven't tried it for using volume buttons to skip tracks. You may want to check this out:
Most custom ROMs have an option to long press the volume keys when the screen is off to control music. This Android app does it on any Android 8.0+ device!
www.xda-developers.com
SD maid still works without root but I am not sure about clearing temp files. You could probably use a regular file manager app for that.
I used to root everything but now I find it unnecessary due to advancement of the phones and the apps.