Why is USDT bad?

I've heard a lot of talk about USDT lately, and I'm curious why some people consider it to be bad. As a professional in the field of cryptocurrency and finance, could you explain the reasons behind this negative perception? Is it because of its stability issues, or is there something else I should be aware of? I'm trying to get a更全面 understanding of the cryptocurrency market, and I'd appreciate it if you could shed some light on this matter for me.