In terms of reversibility, then yeah, really the only completely safe payment method is cold hard cash. Any electronic fiat method can ultimately be reversed, although some are obviously much harder to do than others, and with PayPal it is almost trivial to scam the other party. I generally stick to cash or bank transfers when trading peer to peer, and have never had a problem with someone trying to reverse a bank transfer, although I am quite selective with whom I choose to trade. Look for other parties with good reputations and you'll likely have zero problems.

My favorite DEX - Bisq - purposefully does not allow people to use methods such as PayPal which can easily be reversed.