i just try the withdrawal for PEPE coins and IMO the fees that we need to pay is pretty high because it was around 16$ but don't know if this fees will be lower because right now the gas fee on ethereum around 35 GWEI.
The Ethereum gas sites that recommend how much you need to pay in fees are showing data for ether transactions, but not for smart contract interactions. PEPE is a token and requires more fees. Maybe 50% on top of what you would pay for a typical Ethereum transaction, depending on network congestion. But it still shouldn't be close to $16 if the recommended fee rate was 35 GWEI at the time you sent the transaction. It's not a secret that casinos earn money when you make withdrawals, so that's what this is.
There are some exceptions from that rule like Sportsbet, Livecasino and few other casinos, but I am always asking from all casinos to confirm if they are charging additional fees
Those that you mentioned aren't exceptions. Their minimum withdrawal amounts are 0.001 BTC, but they cover the mining fees from their end.