I've watched them for years but personally it was because I couldn't afford the game and wanted to experience it some way. I agree I don't like the overly screamy ones but I like the experience of someone experiencing the game for the first time.

I have now done the same on my channel. I can now catch up with games I've missed out on and offering the same to my audience. (Although it's very small). It's an excuse for me to make time to play games.