The creation of Tether is not entirely redundant you see during the bear market for crypto traders (and maybe investors) it was a  means of safe haven for protecting your capital from incurring any more losses in the market that is why it is also called “stablecoin” because it is one of the few unaffected cryptocurrencies out their when the market is shedding blood. It may not act entirely on it's purpose but for me this was a useful alternative compared to cashing out your coins entirely out of the market.