hey, that they are file sharing websites or systems around doesn't mean other people who have interest in that same field can't venture into it anymore, take a look outside Crypto, there are several people doing the same type of business and they all doing fine, and it's also good for you as a buyer as the more the competitions, the better price you get, now, look back into the Crypto space, there are several crypto exchanges where every can buy and sell their BTC, now all this exchanges do almost the same thing but yet, people don't use just one, as all the exchanges don't always offer the same token, so please don't make it look like the guy is doing something that is not likely to succeed if he's serious and put effort and time into it