Well USDT is the most stable coin i know on this market and very useful IMO. because i always use it when it comes doing trading which is in order to protect my money despite of the fluctuation ..and it's very reliable and im thankful that behind of this so volatile market there's a srable like usdt that can help us to minimize losses.
USDT has a longest history is a stable coin. There are other stable coins born later, so by now USDT is the best one if you are looking for stable coin. Despite of some drama about reliability of USDT that popped up from time to time, we have still not had better stable coin than USDT, so far.