They already solved it. Premium was way cheaper before they started bundling it with Music which is just utter garbage. I’d pay like 5€ / month for YouTube Premium without Music IF the experience was actually good and they didn’t shove shorts in my face everywhere like that non-dismissable panel that breaks up my subscriptions now.
I think a lot of people would subscribe if they had a lower price tier where they have a reduced amount of ads (like an ad every few videos). Without ad blockers, youtube is unwatchable, you get more ads than you would on TV (where in many places ads are legally capped at around 15mins/hour).