If they offered a light version that was JUST ad-free YT, I'd subscribe in a heartbeat.
I already pay for two other music services and have no interest another one so the $20/mo is too steep for my blood (for the family plan).
YT apparently trialed a YT Premium Lite in Europe [0], which is at a price-point I'd be willing to pay (7 EUR). That's on par with what I'd pay for other streaming services, and that's probably 50% of my streaming source, especially with the amount of learning content on there. I'd probably be willing to pay up to $10 USD/mo for just ad-free YT.
But the other ~$10USD/mo for an unwanted service doesn't appeal to me.
[0]: https://www.theverge.com/2021/8/2/22605455/youtube-premium-l...