The music nonsense is bundled because YouTube is full of music videos and music in the backgrounds of videos and they have to pay the record labels to play the music in. They have "YouTube Premium Lite" that doesn't include music, but then you get ads on videos that have music in them.
This makes no sense, it's not hard to filter out music videos, and music in regular videos wouldn't cost the same as the whole music premium, also Lite isn't just about music:
> Ads however may appear on ... Shorts, and when you search or browse.
So again, you can't pay just to replace ads. (By the way, there is another huge difference - premium is a subscription, so not tied to ad time replaced)
