For real? as a crypto payment users and i will be disagreed with your opinion. This is caused by the fact that i prefer to use the payment gateway that developed by the exchange site like binance.
You can also see how many people are using binance pay compared with this service. Your title was not true. Dominating the payment space is an impossible thing.
The exchange site is in a better position to do this caused by it has so many things that support to develop the payment system like integrating it with its exchange site. This will make people will be able spend their assets easily.