I agree, Tether had been fined because of their lies about USDT being fully backed by USD. Besides Tether is centralized unlike Bitcoin, meaning the developer can tweak anything according to what they wanted. besides, they(Tether) can blacklist any address anytime.
I had to use Tether for few weeks to have them for a trade. It was hard time and stressful knowing that anytime anything could happen. It was unlikely though that with that short period of time anything was going to happen but you know it's the stress you take. Once I exchanged them in BTC I was in peace LOL
You might also think that it is 100% backed by US dollars, but it isn't. So stop comparing and saying that tether is better than bitcoin.
It's a completely lie.
This is a good read.