personally my trust in USDT dwindled the day I discovered it's not completely backed against the dollar currency. It's quite shocking that they keep printing and issuing fresh USDT into the market but yet we can't see much influence on the crypto space. In my opinion, only my local currency is safe 
Not completely but with over 70% fiat backing and others asset. It has a lot of legal biding within and outside US, and had been under series of investigations the past years and still in market. Some opinions on the coin speculates a strong influence on bitcoin price, though less than $4b market but will see more supports with strong interest.