There is no connection between Ethereum and the stablecoins on the basis of them keeping ETH alive. The Ethereum blockchain is just one of the blockchains in which those stablecoins run and without those stablecoins, ETH will exist. Likewise without the Ethereum blockchain, stablecoins will exist. Now we have more chains such as TON, TRX and others where more stablecoins are traded than ETH, yet ETH is still doing so well.
Yeah but those chains are mostly asian chains that have their HQ in asia and Trump does not want asia to have the most crypto market dominance otherwise USA will fall vehind, lose world reserve currency status and asia will be the most financial superpower with china leading the way.