Wolf is not the only place with high withdrawal fees, I know a few more... I am not sure how things are going now with Ethereum, I stoped using ETH and tokens on Etherum network a while ago...
You can come back with Ethereum and ERC-20 tokens because transaction fee on the network is cheaper in past weeks. It is still higher than in early of 2020 because the fee is a multiplication of Ethereum price and Gas price. Gas price drops too good rates but Ethereum price is still high.
Stake, Primedice etc charge $7 as the withdrawal fees which is better in comparison, but it still needs to be lowered. $20 withdrawal fee is ridiculous. They need to learn from casinos like Bitcasino, Betchain etc that charge zero withdrawal fees.
I think it is not fair to waive the fee because companies have to do set up, operation and maintenance for wallets, accounts gambling operations and more. They can charge cheaper fees but I don't think all companies will waive the fee as a must condition.
Also, it's quite ironic that the fees related to the most popular cryptocurrencies(BTC and ETH) are extremely high in recent times.
I agree, it is ironic and gambling sites as well as exchanges need to be more flexible with transaction fees for customers.