It's not easy to build and run your own crypto exchange, although it's challenging to look at but it's hard to do apart from the need to spend a lot of money, there are actually a lot of things to consider here. Although, if you do it right you can expect to make a lot of money here.
Just in terms of complying with the laws and regulations so that you can operate, there is a lot to be followed and done here. The secure funds must also be fixed, and the management of the possible risks that can be faced here.
But this is just my opinion based on the title you made here op that's why I said it.