What makes you think the spread on turning Pesos (-> BTC) -> USDT, or vice versa is any better? Market makers and exchanges don't work for free. And since you

What makes you think the spread on turning Pesos (-> BTC) -> USDT, or vice versa is any better? Market makers and exchanges don't work for free. And since you can't buy groceries or pay rent with tether, and you need to convert it from/to fiat, you're not actually solving any problems by using it.