Use a platform like this to buy or sell bitcoins, is a High-Risk move, i wouldn't recommend anyone to risk their money this way because if you lose your money the platform will say "It was a P2P exchange and we are not responsible for your loss".

My question is, how does the platform avoid scammers if there is no KYC process on it? Anyone could join with a fake name, offer Paypal, and after the deal then charge back the Paypal payment while they already get the BTC.

the idea isn't bad, but it will be a paradise for scammers with the current rules.