I’m not sure if you have checked out WoW lately, but it’s actually a pretty beautiful game. I think generally they want the tech specs to be a low barrier to entry for a game where they want millions of players playing concurrently. It also cannot be super heavy or things like raids and battlegrounds would chug.
It sounds like you might be misinformed - a YouTube Premium subscriber watching your YouTube videos is worth, IIRC, 5 to 10 times more than an ad supported view for the content creator. I know a number of content creators have indicated as much for years - I wish I could cite a specific WAN Show episode from Linus Tech Tips who I’m certain has talked about it many times.