Every coin launched on dexxed is priced in $DEX. Every buy of every one of them buys $DEX first. More launches, more volume through the register.
Coins on dexxed are quoted in $DEX. A buyer's SOL becomes $DEX before it becomes the coin, on every single trade.
The treasury's share of every coin's creator fee is paid in $DEX and funds the dexscreener payments. The wallet is public.
A free dex brings more devs. More devs means more coins paired to $DEX, and more buys flowing through it.