You pay 50% fee only if you request a withdraw every day and I think you don't want to do this.
Do no try to put this website into a bad light.
Withdraw fee is only when you withdraw, logic yes?
If you invest 40$ and after 30 days your earn is 20 withdraw fee is 0.2$ + 5% that means 1.2$. Where is 50% fee that you talking about?
These kind of sites do not have any guaranty that how long it will survive so every investor prefer to take their investment and profit as soon as possible. No one will put money and wait for 30 days.
We have many examples in this forum, sites has been closed even after couple of days. That's why we prefer to withdraw as early as possible.