Some casinos have high withdrawal limits and accept USDT, but they don't accept other cryptocurrencies like Ethereum, Bitcoin Cash, Tron, EOS, or XRP. Why do you think that is?
Have you given Luckyfish a try? They offer a variety of games and actually payout winnings. Plus, they support numerous cryptocurrencies and have responsive live chat support available when needed.
King Billy allows to deposit with the USDT and make payouts. The only thing I don't like here it's that the maximum weekly withdrawal limit is $/€ 20,000, and the maximum monthly limit is $/€ 40,000 (or currency equivalent).