I listened to his interview on the Joe Rogan show and was really impressed.
Mr. Beast built his channel by taking all profits from each video and plying it into the next video. Using this approach he was able to produce progressively larger and more expensive videos. He has demonstrated his frugal lifestyle, has publicly given away an incredible amount of money to good causes, and has stated his future goals for his businesses will be for charity. Everything about his actions strikes me as genuinely good, it just seems like the publicity is the best way to get more money to accomplish the charitable goals.
You're right that what he's doing does not conform to the definition of altruism specifically, but that doesn't mean what he's doing is not good.
How can you watch the video where he pays for the blindness surgery for all those people and say that that was anything other than an amazing win for all those nice people?