That can be the reason why they stopped or it's about the volume that they're getting and it's no longer enough to support the bookie so, they decided to dive into another venture for most casino games.
I doubt you can cheat on the odds since they still get a 5% cut no matter what their players bet on and even if you do get better odds it's very easy to turn it around knowing the volumes aren't that high. With that said volume is the main issue since the parimutuel style of betting isn't that common in crypto sportsbooks compared to the fiat and skin betting sportsbooks. Also it's really discouraging to make a bet when you see low volumes on most of the matches they offer and that only hinders the growth of their sportsbook so you can't blame them for pulling the plug after a few years.