Ok look, I have a stake here because I run a crypto fund but let's just be clear: in the beginning of money, refunds involved going to the person you wanted a refund from and demanding the return of your currency. It's not that different from how crypto works right now except that the transaction is much more provable. Over time, institutions that look a lot like banks will provide the refund abstraction on top of crypto, BUT that doesn't change the value of an immutable changelog for money.

Think of it this way, if you were building money for computers, it would have atomic transfers and a changelog. Those properties, it turns out, are very useful, mostly because people dramatically underestimate how many transactions are between semi-untrusted parties (I would argue it is the majority of transactions). Yes, right now, crypto is a step backwards for many transactions, but that's because institutions that would traditionally support currency can't properly model the risk so only the brave entrepreneurs who accept unbounded risk participate. Over time, like any technology, traditional institutions will accept it as the regulatory regime becomes more clear.

The analogy to the beginning of the internet is obvious (the only real question is whether governments decide to ban it).

Refunds not a big deal and no different than paying cash. Online stores have a reputation and reviews so if there's retailers out there scamming people the internet will find out quickly.

To be fair -- and I'm no blockchain booster -- transactional rollbacks should be modeled as separate operations and replacement transactions on an immutable log (or loggish thing, anyway). You can use bitemporal tracking to model invalid belief states, but your system should never be allowed to drop transactions.

Yep, they generally are in modern payment systems. A chargeback is a separate transaction that has to be initiated, submitted and paid for.