But just as in that episode of Sunny where they try to issue Paddy’s Dollars, it’s because everyone wants to be the one whose currency is the most widely used coin, because the network effects would make whomever has THE stablecoin very influential/powerful
You don’t need stablecoins unless you want to buy other currencies (and you technically don’t need them to do that, but most exchanges require the USD->stablecoin first). The issuers want to end up being a Visa/MasterCard. (They don’t issue USD, but they do make a killing from transaction fees.)
To your last question about "Has anyone found uses them?" that's what Web3 was about. What good is my Power Card if there are no D&B games to play? There were kernels of good ideas in smart contracts, DAOs, etc. but they have been subsumed by grift and treating coins as investment, at least for now