And people are still using Tether since they're believe it's pegged by real fiat US

while the fact it doesn't.
Bitfinex aren't really good exchanges and has several accusations in the past, better to stick on popular exchanges (e.g. Binance, KuCoin, Coinbase)
Tether is just printing ...and nothing more. It's not backed by anything. I don't think they are 20% backed of REAL money...