question FOR EUROPEANS ???????? convert USDT to EUR before buying BTC?

I have binance lite, I'm not a trader but I invest every month approximately 100€ in btc or more if there's a dip like rn. Also I live in Europe

I'm just wondering if I do it the right way? Basically I buy BTC - > select BTC - > 100 EURO and that's it.

But I saw some people telling to first convert USDT (who is a stable coin) to EUR and keep it in my wallet and THEN convert those usdt to the crypto I need. So from what I understood if I do this with 100 euro I will have ~115$ and second step is to trade those 115 usdt to btc (or any other coin). So that when I will sell I won't have any taxes to pay (because my country works with EU)

So I'm wondering which is the best way? And if all of this is "worth it" or will I obtain the same results? I never Selled btc yet and I'm not panning to do it in the next few years so Idk about the taxes