I understand your answer is in good faith, but it still sounds like the same generic answer given when someone questions the engineering quality of any other popular product or service.
The fact is that plenty of teams are mature and professional and yet most software still suffers from bloat, slowness, bugs. Why would React be different?
Preact, for comparison, is only 5kb or so, and has almost 1:1 feature parity. It's not fully drop-in without the compat, and even experienced React devs can nitpick about it, but that's not the point: the mere fact that it exists and gets the job done is enough to raise doubts about the need for React to be quite big.
Does React need to lose weight? Maybe, maybe not. But I don't think it's good to shut down those discussions.