Meanwhile, with a credit card I can buy a product from Amazon or some joe-schmoe site nobody ever heard of, and have a guarantee that Visa will back me up if the latter is a scam.
At any rate, the advantage of Bitcoin/Ether is that sending Joe Schmoe your money doesn't mean you've exposed your credit card number and billing address (likely also your physical address) to Joe Schmoe. So there's pros and cons to either system. Refunds have existed since well before credit cards were a thing. Does it require a bit more of "buyer beware" ideology? Sure, but I don't think that's any different than a cash-based society.
The move to chipped credit cards (or Apple/Android Pay) also shields my real card number and makes information unusable in case of hacking. I already hide my address by having the card statements go to a PO Box and using that as my billing address, but I know that's not a widespread practice and some institutions forbid that.
I've been in countries where there are major trust issues with taxis, and the very worst case I could imagine would be a service which signals to anyone watching that I'm on the street in the middle of the night, holding a smartphone which also has the ability to make irreversible transactions of a large portion of my cash holdings to an anonymous endpoint, and I'll probably get into the next vehicle to stop for me.
For a significant proportion of mooted cases where trustlessness is mooted as an advantage of blockchain technology, trustlessness doesn't actually exist and/or centralisation actually reduces problems with trust