Tether will just be replaced by other stable coins if it turns out that Bitfinex can't back them if there were a run on Tethers (the only scenario we would find if this were actually true). There are alternative stable coins which will rise to compete with Tether and balance out the market, including Circle's USDC (https://blog.circle.com/2018/05/15/circle-announces-usd-coin...) and the ETH/Gold-backed MakerDAI: (https://makerdao.com/).