Would you play a warlock with an unknown entity that chose your spells for you or does that feel like you're robbed of creative agency? What if you had abilities you chose but randomly bestowed boons you didn't see coming? #TTRPG

I'd find that so fun as a kind of dialogue with the game master. It would be fun to be kept on my toes and just work with what's coming. Definitely a your milage may vary situation, though, that has to be based in trust and negotiated consent for parameters.