If Kraken is your main choice then you're in luck. Kraken is also one of the very few exchanges with a direct USD/USDT market. You can send your USDT straight there and exchange it for USD. No need to lose extra in trading fees and volatility. Kraken's USD set up is pretty creaky compared to elsewhere but at least it exists.
https://trade.kraken.com/charts/KRAKEN:USDT-USDHow much cost fee withdrawl USD in Kraken?