Did you even watch the video? There were no ads in it, and the part where he warns his viewers that he will never ask them for money is the whole thing he's talking about, that scammer bots are impersonating him in his comments and trying to trick his viewers.
First, use a good adblocker, like Ublock Origin. There's no ads in the actual video the Professor posted.
Secondly, his audience is tabletop card gamers. He does set the scene as to why he's making a video. Most of his audience is not of a technical nature.
I also made a synopsis as a comment so you didn't have to watch the video, since some (including myself!) despise video-only content. But I do follow him on YT. And his problem applies to a LOT of areas on YT, Twitter, Facebook, Reddit, and elsewhere.