Of course he's a serious politician, and a skilled one at that. He has managed to greatly strengthen ties with the US, outmaneuver most of his political 'enemies', keep the flow of western weapons coming into his country and get the entire western world to kind of shrug and forget that he had a journalist murdered and cut up with a bone saw.
I wouldn't really go as far as qualifying him as a successful politician for the simple reason that it not really challenging for dictators to consolidate power and build alliances using unethical means, like money and intimidation and in this case murder. For MBS his father is already the monarch of one of the wealthiest nations on earth, which I'm pretty sure helps a lot.
I don't know Saudi Arabia well enoughto judge about this political enemies. I have read he has made some progress in modernization. Hi megalomaniac "neom" project seems to have failed, at least stalled. He has alienated Qatar, he has sided with the Israelis which could backfire easily from Muslim extremists.
Of course he's a serious politician, and a skilled one at that. He has managed to greatly strengthen ties with the US, outmaneuver most of his political 'enemies', keep the flow of western weapons coming into his country and get the entire western world to kind of shrug and forget that he had a journalist murdered and cut up with a bone saw.