The withdrawal is taken in tokens, not in ETH. This is a first difference. The second - the withdrawal is happened by batches, so each included TX have only part of that fee, calculated in ETH.
All other points are valid (except fee in tokens - it uses price of the token) and understandable.
This is why it’s opt-in.
However, I have not tried it on mainnet because of high fee. My test results are here: