Players who do not want bonuses and play with the money they deposit make requests for withdrawals whenever they want.
Investment and withdrawals are done manually.
That's where mostly you'll not be able to gain many users if all the transactions like withdrawals will be requested instead of automation. I have the same experience with a gambling platform in the past and that's what I don't like with it because it's really a hassle.
Withdrawals like $20k or more should be the one being processed manually but if just a hundred bucks I don't think that's a good PR, I don't know with others, just even my one cent.