Not really, because not everyone can win $50 in one game or even multiple gambles. So lowering the withdrawal amount might help small gamblers to withdraw their winnings. For the amount, they can adjust it with transaction fees.

I try to understand it. If we deposit $100 and complete all missions, we get 180 free spins.

The 100 free spins are obtained from the $100 deposit, while the 80 free spins are 20 free spins to login in the next few days, 20 free spins from the second deposit (with a $10 minimum deposit), 20 free spins if we bet 20 EUR, and Another 20 free spins if we bet 10 EUR.

So the mission that we must complete is that we have to log in in the next few days, make a second deposit, and bet 20 EUR and 10 EUR to get an additional 80 free spins. If we don't complete the mission, we may get fewer free spins. But from a $100 deposit, we can get 100 free spins. Maybe so, but I could be wrong.