Do all DEX have a native coin and why?

[Gposas]

Do all these decentralized exchanges have a native coin?
And why do they have a native coin?

[Freemind]

Good question, I think so, that all DEX (and almost all CEX) have their native coin/token. The reason is very simple, self-financing, having their native currency the DEX and CEX can make withdrawals cheaper, thus increasing the value of the currency. They also use it for promotions, business contests, and other things to attract more investors. The most popular is Binance's native coin BNB, which laid the groundwork for other exchanges to create their own coin.