I signed up back when it was “Google Play Music” and was locked into that deal as well. I didn’t want to lose it, but I wanted to upgrade to a family plan. Customer support promised me that if I upgraded, my family plan price would continue to be honored for just as long as the individual plan price.
Spoiler: they lied.
I had my account using a unique-per-service card with a monthly cap and it started rejected their billing attempts when, about a year ago, they abruptly increased my plan price to nearly double what I had been paying.
I had already been using uBlock Origin and Tidal via Plex (even though I don’t actually use Plex, but when I signed up I hadn’t yet decided to use Jellyfin), since I despise the YT Music UI, so for me there wasn’t much of a change.
That said, if you like YT Music / YT Premium then by all means stick with it. The creators of the videos you watch get comped better when you watch them than when a free user does - that was the main reason I kept my subscription for as long as I did.