Actually there are many exchange making thier own coins just to follow what binance success story.
Having thier own coins and make thier own demand is what binance do to BNB.
But those copy cat do not have anything to offer other than you can use it to thier exchange and lessen the fees for widrawal.
There are many of them even new exchange before they launch make thier own coin to think that they can also earn money having that.
success of binance  (BNB) will not gonna happen to other exchange unless they invented other use of thier coins and can also list to other exchange.