If gambling on pro-games were a in-game functionality I may bet some ugly items but I am not logging on a 3rd party site for that no matter how safe they may tell me it is.
But I can definitely see the appeal of betting on a match, specially one between 2 teams you don't care about. The idea of winning something and having picked the right team adds an extra spice to what could otherwise be a pretty uninteresting match.
Probably gonna restart my Doom run on a harder setting because right now is pretty easy which makes looking for the secrets kinda futile since I'm already dominating with what I have.