I have used bitcoin in all the trades I have made so far, I have never used US dollar nor Tether. I believe that trading with cryptocurrencies especially bitcoin makes the process of trading easier.

Besides, with bitcoin, you might be able to get more altcoins since the value keeps going up. For instance, If you receive 1 bitcoin and decide that you are going trade altcoins with it. It might happen that you decide to hold on to it so that the value increases before actually consider making your initial investment. In this sense, you will be able to grab as many coins as you have never expected.