No, they may seem to appear "friendly" but in the longterm you'll never know what will happen to USDT for example, the company holding the funds may go bankrupt, they might have administrative issues and many other potential factors that may cause a downfall. I don't really like it when people invest in "stable coins" and use it to trade. One day, people may wake up to USDT being worth absolutely nothing and there's no comeback.
I completely agree with you, and whatever has happened in the past with USDT reserves, this all can fall down as a house of cards. Meanwhile what are your views with MakerDao, I think DAI is the only stable coin which is decentralised and stable in its true sense.