I think the sometimes excessive criticism comes as a direct push back against the pretty gross overhyping of him that's gone on since he started doing well at Dortmund, and certainly has ramped up exponentially since the Madrid move and all the Zidane noise started.
He is good player with some high quality attributes and a lot of flaws. But it's harder to judge him objectively because of the hype train around him. That's not all his fault but he's got a lot of maturing to do still, no matter how much his well spoken interviews convince the Bellingham lovers that he's mature so far beyond his years it's crazy.