I think he isnt humble and he is a bit of a whiner actually.
Remember that offensive offsides call against the chiefs vs the bills (which the guy absolutely 100% was offsides, on offense.... like it wasn't even close), and Mahomes absolutely threw his toys out of the pram and blased the officials during the game and after, despite it clearly being the right call?
Then the altercation with Justin Tucker before the Ravens game, totally unecessary.
Mahomes thinks he's bigger and more important than everyone else, and it's starting to show through.
I personally think he is a smug and smarmy little baby man and while I dont think he is overrated, because he is ridiculously good at football, I don't like him as a person from what ive seen at all. As a person outside of that, I cant really say because I obviously don't know him personally, he might be a good dude overall, but I just dont buy the narrative that he is humble and a total saint.