What if that merchant was your friend? Or someone you knew personally? What if the merchant was recommended by someone you trust, like how small business has worked for millenia?
Otherwise, yes, you're right, you shouldn't buy things from people you don't know and/or don't trust, even with the ability to request a chargeback. That should never change.
> We have these systems in place for a reason, and it’s to stop uncivilised merchants from doing what they’ve been doing as long as merchants have existed.
No, that's not at all why these systems are in place. They would never have come to be had the U.S. Congress not passed the Fair Credit Billing Act in 1974 [1], which essentially outlined the mechanics of chargebacks, amongst other billing "errors".
To boot, consumers aren't a blameless party here. Fraud has existed on both sides of transactions since trading was a thing.