I came across Create Thrall when I was making my character for Curse of Strahd. I decided to go with Goolock for thematic reasons, and made a list of every way to incapacitate someone in 5e, even knowing the campaign doesn't get to level 14. Hypnotic Gaze still stands out to me as the clear winner for being recyclable and also a really strong ability on its own, as well as not (RAW) breaking Sanctuary.
I still think Goolock is weak (this can't affect non-humanoids, which I find a little disappointing), but nowhere near as weak as before. Honestly, this could make a GREAT villain.
This is true, although ways to do this in combat are limited. The torpor poison is the only non-magical way to do this if you don't count unconscious as being asleep (which, technically, is a better description), although all 3 other poisons inflict this condition, as well as Eyebite.
It's true you can just wait for the target to be asleep, but the point is that you can do this mid-combat over 2 turns and there really isn't much anyone can do about it.