I guess that really depends on what you want out of your thralls. If you want an “AI companion” on your adventures, then yeah, they’re not anywhere near that. If you want a meatshield who can take the big hits, defend your base (and optionally carry stuff for you) while you stab enemies with the pointy end, they can do that fairly well.
Thralls are fantastically better now than what they were like in past years. That said, I don’t see them integrating any kind of adaptive AI into a 6-7 year old game engine.