After what happened to UST. Many crypto users are now choosing BUSD and USDC. because these two Stablecoins conduct regular audits.
Meanwhile, USDT in terms of audit, regulation and underlying storage is less transparent. so many sell it and switch to USDC and BUSD. maybe this is also one of the reasons. Moreover, there have been problems in the past that have tarnished the reputation of USDT itself. although USDT at that time was able to solve the problem well. But people are still afraid and feel that USDT is still a high risk.
I would say that people do not even pick those anymore. USDT lost a ton of blood, there were 10+ billion dollars worth of withdraws from there, and they had to cash out so much to pay for that much leaving them all at once but they did it, each time is a bit of a problem for them because they invest into liquid assets to make a profit as well.
Secondly, USDC didn't grow all that much and neither did BUSD but that could be mainly because of the market going down as well, people might be leaving all together instead of just turning their crypto to stablecoins. This UST deal was just something major and hurt all of the market and not just even stablecoins.