The bear market has immensely increased the demand for USDT with how it is the only safe haven asset on exchanges like Binance. The majority of the traders value their holdings according to their USD value, and will do everything they can to protect it, which means that USDT is the only option to go with. In other words, the utility of USDT is there, regardless of them being actually backed by fiat or not.
We all have our rightful doubts about USDT. I'm quite certain that Bitfinex used non backed tokens to pay off its post "hack" debt, but we can't prove that it isn't backed, so they will continue to ride people's benefit of the doubt, possibly for many more years to come.
We can only hope that more exchangs will end up becoming fiat entry/exit points like Bitstamp, Kraken, Coinbase, etc. With enough time, USDT dominance will significantly decline.