If its anything like paxful then you should be able to trade without KYC up to amounts of 8000 USD, there were traders who wanted KYC and others who didn't and even if you had to buy from a KYC only trader, its negliable in any African nation to buy someones ID for $4 and KYC an account

As for the stablecoins, I don't use them, but alot of people who do buy them are looking to settle payments for goods and services, especially cross boarder, if I wanted to purchase something in Zimbabwe, its simply the cheaper option with lowest vol between settlement