The answer is easy.

Arbitrage betting makes you win in the long run. As you are already aware, most gamblers lose in the term. If the players were the winners, then the casino would be the loser.

Since both the player and the casino can’t be the winners at the same time, the casino can’t afford to have long term winning players making bets on the casino.

That’s why in the ToS they usually ban arbitrage/EV betting.

If you can’t handle this, don’t play.