I always felt a little off about him, so I subbed and have been watching his content for a while now. As light entertainment, his videos are pretty neutral and can encapsulate certain historical events and people relatively well, and if you don't take it too seriously, I doubt there is much harm in watching him. Looking to him for some type of deep analysis however might not be a good idea, and I never thought anyone would take him as anything more than a regular commentator on Youtube.
I began to wonder about his upload rate. There is no way anyone could do a thorough analysis of anything at the rate he is going at it. This makes me believe, that he is very quick to pick up on words and lingo to portray himself as an expert, but that he lacks any thorough understanding on subjects. This would mean that he is intelligent to some degree, but lazy, and possibly suffers from some of the issues he himself has spoken on.
I eventually caught him slipping in one of his videos. I can't remember what it was exactly, but it had something to do with weapons. He spoke as if he knew something about firearms. He seemed to repeat a lot facts about weapons, but then he totally messed up on a very obvious point about what he was talking about. This happens a lot to people who pretend to know, but who haven't done any actual research or have no actual background in the subject they are speaking of. It happens to all of us sometimes, where we repeat something we take for granted, but this was actually something that I had subconsciously picked up on when it came to him, but I hadn't been able to articulate it to myself. I feel as if he is pretending to know a lot, but in actuality knows very little about what he is saying. He is intelligent enough to pick up on the solid ideas of someone else compared to some incoherent claims of others, but he seems to mess up when it comes to some counter intuitive or experience and knowledge based reasoning. Like if an experienced chess player just knows that some moves are not great, and no matter how high your intelligence is, you wouldn't be able to figure it out without actual experience.
Also, I have commented on his videos only once to my recollection, and it was about the depth of his analyses. I had just spent a week following an actual trial. Grande did an analysis on the trial, and it was very superficial. The response from his followers was a bit unnerving. One of them went on my channel, tried to find information on me, and then tried to weaponize this information against me, simply for calling the analyses relatively superficial due to the upload rate, and my knowledge of the actual trial. This comment from his follower seemed to gain traction, which also unsettled me. If this was the type of crowd he was gathering, there had to be something really wrong about his presentation that I wasn't completely picking up on.
His examples and opinions on certain mental disorders have seemed to have a very personal touch, like he might have been accused of some of the traits that he is critiquing. It was in one of this older videos about narcissism or something that had a particularly personal vibe to it.
He has often criticized Dr. Phil on his channel, but I do feel that even though he is definitely not as bad as McGraw simply because his has less or an impact on society, he is treading the same path. The difference is seriousness pretty much comes down to Grande not having the power McGraw does. I also feel that McGraw actually has a lot more personal experience in psychology than Grande does.
All in all, I would avoid watching him solely based on the huge question marks that surround him. If you are knowledgeable in these subjects, like law, psychology, and so on, you should watch him, and critique him on his channel as much as possible.