There are more "stable coins" every day. I think that their creators figured out thats free money. If US treasury can create money from thin air why wouldn't many others? 
Interesting thing in all that is new coins tusd, usdc and others are taking part of the market cap but usdt is not loosing any of his?! 
Interesting thing in all that is new coins tusd, usdc and others are taking part of the market cap but usdt is not loosing any of his?! It's because of Tether's printing abilities they are always increasing the supply to keep the value stable with people dumping mostly.