Wrong.
They can do something about it.
If I owned an exchange where the only trader was me, buying and selling btc constantly on my platform... you, as the owner of CMC, would you list my exchange?
No? What if I paid you some? Yes?
This is what CMC shows right now, last 24H "adjusted" trading volume of BTC.
In this whole page, the only legit exchange is Binance and the rest of them are completely bogus. Fake. Fugazi.