By the way, you need to know that USDT is present in different blockchain networks. I wonder if the risks are also different?
I don't think being on different blockchain reduces the risk. The rating is about Tether that uses USDT ticker operating on different blockchain. It is one of the most shady stable coin which has the third biggest marketcap. Those who are using it won't stop using it because it is available on different blockchain that is their USP.