I do love to listen to music while watching text YouTube videos, but I can't because YouTube can't be muted.
I use the respect audio focus in Musicolet Music Player.
I have tried App Volume Control but it did nothing!
You can play video in browser instead of youtube app. In browser you can mute the audio.
If your browser launched youtube app when clicked on video link, you need to copy the url and paste it inside the search box - youtube video will load in browser.