There's tonnes of stuff out there from HKD, AED, SGD, CHF stablecoins... most track USD anyway (i.e HKD, AED, SGD debase and strengthen inline with the $) and CHF generally is stable against it as they are all proxies for the Dollar.
You then have treasuries on chain etc, gold on chain etc... and even non USD USD stablecoins (i.e not US firms or holding US Funds in US accounts/treasuries) but either proxies $ in overseas banks (offshore) or similar set ups.
The only reason USDT/USDC is successful is because its︀ so liquid and it's basically American or protected somewhat by rule of law in the︁ US.
Once those are banned you'll see the EURODOLLAR equivalent of explode.
That will be︂ the ones mentioned above or even things like what ever is replacing DAI, the world︃ wants Dollars, and even if the US bans it in the US others will find︄ a way to provide the market with what it wants without the US having jurisdiction,︅ just like the EuroDollar market, the US has no say on this and can't dictate︆ when they are not using US financial institutions