I think it is not wise to use stuff like USDT, if you want fiat, go with fiat, if you want crypto, go with crypto, never trust your money with some stranger telling you that they have your money and will give it to you whenever you want, thats a shady business model from the start anyway.
Go fiat is easy to say but actually its not as easy. I mean you would have to transfer money to banks and then withdraw again when you want to buy Bitcoins. With USDT or any other stable coin you save a lot of time and transactions because you can immediately use them. I myself don't like the idea of holding a crypto which is centralized and the reserves are unknown but then there are other stable coins like Binance stable coin BUSD which I think the people who use Binance can trust. If you trust Binance as an exchange there is no problem trusting the stable coin they introduced.
Also forgot to mention there is a coinbase stable coin which has continuous audits and is way better than Tether in terms of legality and transparency so one can use it if trust and transparency is an issue.