...But if you had to go with only one, which would you go with, and why? ...
If your goal is only trading, then the best choice for you will be KuCoin. In addition, launchpad is also available on Kukoin without verification in addition to trading, while on Binance there is no possibility to work without mandatory KYC at all. In addition, the main difference between these exchanges is the volume of trade and, accordingly, liquidity, where Binance is the absolute leader.