“rentseeking behaviour” is one of the dumbest things I’ve ever heard used to describe a subscription service.
Is that all this is - you dislike subscription services?
They can’t gatekeep something that is available freely and easily outside of their service. They’re putting their implementation of the lyrics being matched to the music inside their subscription service. That’s not “gatekeeping”.
You still haven’t explained how anyone “stole” anything either.