When I have to compare both games currently I would say Wrath is way better. But how much you can compare them is debatable and not only because of the different state of development. Owlcats games are more grand, they need to be as they are adding kingdom building or crusade leadership into it. They also have the advantage that they do not need to create the whole story by themselves but are implementing published adventure paths (although with a lot of modifications which so far made the game better).
Whats definitely better in Kingmaker/Wrath are the companions. The Kingmaker ones were already better than the BG3 ones as far as I can tell (even when they were a bit stereotypical in Kingmaker) and the Wrath ones look even better.
But you see a very different way of design in the Owlcat games and Larians BG3. Owlcat goes wide and include lots of subclasses, even obscure ones, and even creates more subclasses themselves. And for DLCs they add even more things like companions. Larian in the other hand goes into detail with full voiceover and cutscenes.
What is better? I don't know. It also always depends on the execution.
