But as per the old tradition, such services slightly underpay profits (to put it mildly) to their users for using their capacities. Due to this, the profitability of their service is built. Also, there will be a limit on the minimum withdrawal amount. That is, in order to withdraw the bitcoin (of course, only a small part) you have mined, you will first need to accumulate a certain amount of them, otherwise it will remain on the balance of the service, like NiceHash.