>The other part is that it is not easy to directly trade USDT for USD. Kraken is the only place you can do so directly, it is the only place the peg is directly tested. Apart from that to get USD you need to trade to something else, like BTC or ETH, and then sell that for dollars.

What do you mean? I trade USDC and USDT from and to Fiat using Binance, and it's a breeze. I get the funds directly on my bank account in 5 minutes or so, and I imagine the same happens on Kraken, coinbase pro, gemini/blockfi.