The problem of chess is that it has very low probability influence. I mean that it's obviously who would win (if you know players of course) in the certain game, so betting business is to hard to do it. Games where winner is not determined before game start is rare games (world championships), and betting must be often event, like 2-3 games in a week to bet.
For me, i personally playing a lot at chess.com, so i know what i'm talking about
Well at some point, even the top ratings with 2800 are being defeated by 2700 ratings.
There are recent tournaments that GM Magnus Carlsen wasn't on the finals. Same with other online games, there are teams that you knew are undefeatable but being defeated by a rising team, those scenarios can always happen.
Well, chess has it's last renaissance during the 70's with Kasparov and Karpov, I still remember it being played in the streets as sort of past time that time and then evolved as being used to 'hussle', like 3 card monte.
But I would agree that the game is somewhat boring and bettors are looking for exciting game specially with the physical aspect (contact sports). So I doubt it will have the support specially at today's time wherein football, UFC, basketball is the top pick for sports bettor.
Chess is a very difficult game to get into for several factors, one of them is that to get any insight into the game you need to invest many hours in it and even then the top players play at a level that even other good players have a problem understanding which makes it difficult to watch, also the matches last very long and lets be honest watching two players not moving for hours is not the most exciting thing in the world, however I am sure that if we see another craze like the one we saw during the 70’s then sports books may add chess in the future.
Since chess is on the top streaming right now, those popular streamers could influence others to be interested in the game. The problem is, when they knew the term "chess" they think it as a hard, complex, difficult, and very boring game even though they didn't play the game. There's a mode in chess which is blitz, a 5 minutes game and tbh it's very suspense and thrilling if you knew the game even its basics.