You’d have to be historically illiterate to want to throw this stuff away.
I’m sorry your friend got scammed, but there’s a host of damn good reasons we put the risk on the seller.
This is not a set of outdated practices resulting in ‘risk’ to sellers, it’s deliberate consumer protection.
But there are additional, unnecessary risks created by the banking system, and for many transactions (like when the thief stole my friend's laptop, or transactions that result in identity fraud) those risks are the vast majority of the total risk. In those cases, cryptocurrency solves the problem; it doesn't just shift the risk back to the buyer.
Your links to checks are fantastic. Who the hell uses checks any more? Wow.
Cryptocurrency precisely shifts the risk to the buyer, their recourse is gone if the goods they get are substandard. The imbalance of power between merchants and consumers is real, and consumer protections like reversibility are there to address this.
Perhaps PayPal is not the best choice for person to person transactions. I am sorry your friend got ripped off, but perhaps as a seller he should do his research about who he’s selling to. Without reversible mechanisms, every buyer has to research every purchase.
Your idea that cryptocurrency would solve your friend’s situation is just plain wrong. It might have solved it for one party, but it does push the fraud risk onto the buyer. If your friend had sold a laptop to an honest buyer, but the laptop died as soon as it left the house, or was of lower spec than advertised, the buyer would have been out of luck.
I’m not sure why you think pointing this out indicates that I’m upset, I can only presume this is tone trolling.
Cryptocurrencies unilaterally move the risk to the spender and I don't see how that is same as removing risk. A financial transaction is always risky for all the participating parties, there is a chain of liability. You can't make the risk disappear, someone has to bear it and/or underwrite it. Which is why you have all these payment processors that charge x% transaction fees for merchants in exchange for taking on that risk.
A larger point here is disputes will always arise in a business transaction. Which is why we have arbiters who hear both sides of a story and settle the matters. You can't say "Payment reversal is an open invitation to criminals to steal from sellers." and make payers unilaterally liable for every payment they make. That is a recipe for killing a market.
In your friend's case PayPal acted as an arbiter and given that the seller had no proof of sale PayPal made a judgement call to side with the payer. The harsh reality is your friend should have been more careful or said only-cash-accepted.
Obviously any payment method that is a layer over credit cards and US bank transactions is going to want to support reversal; otherwise, in cases like these, the payment processor gets left holding the bag. It's not "the result of decades of learnings and trial and error." It's the result of banking regulations which impose huge risks on anyone who receives money through the banking and credit card system, in order to avoid imposing risks on people who send money.
In many cases, those risks are not inherent to the transaction being conducted; they are introduced by outdated banking business practices that rely on detecting rare frauds after the fact and clearing transactions over the course of weeks or months. Instead of removing the risks, current banking regulations force them on anyone who receives a payment, so the banks don't have to fix them. Cryptocurrencies just remove those risks instead of externalizing them.
And that's why so many payment methods support reversal.