Usually those kind of matches have pretty low limit overall because they are pretty high risk.
Also if somebody already made big bets on that match it could have used most of the limit for it.
they do have low limits but not as low as this , pinnacle bitcoin alternatives usually have these games and the limits are at least 40 mbtc
here is an example today for faze vs godsent , stake is allowing me to bet max 14 mbtc on 1.15 so the profit is barely 2 mbtc while in fairlay I can bet over 2 BTC on that selection
I want to be able to gamble on the coin toss of a football match the next time I can, literally who will have the kick off is something I would gamble right about now because we lack competitions. So, to put a limit on something right now is hurting everyone, both the casinos because you are not getting too much wagering going on and the gambler because we are bored as hell.