There is a difference between USDT/BUSD/ USDC and UST stable coins. The USDT/BUSD/USDC are backed by the physical US dollar whereas UST is an algorithmic stable coin that remains stable because of an algorithm that runs behind it. This algorithm was exploited somehow and it is very bad for the overall crypto industry.
If Luna and UST are unable to recover and come back, people will lose trust in the algorithmic stable coins and the future of these coins will be dead
Personally I had high hopes for algorithmic stable coins as those that claim to have their coins backed by fiat could always create more coins than the fiat they have available like banks do all the time , use fractional reserve banking and deceive people that way, but with this fiasco then it is very likely that the interest in algorithmic stable coins will go down dramatically.