Better bank tech exists in many places outside the US (pretty much everywhere, really). Better bank tech does not guarantee my ability to send you money, and it certainly does not provide that ability if any single one of a number of large private and/or public entities decide to preclude me from it.
Guaranteed access and censorship resistance. That is a clear advantage of cryptocurrencies at this time (not of blockchains, mind you), and I think it's a significant one. That doesn't mean you should use them.
If you are curious and up to the challenge I will give you an Argentina (where I currently live) bank account number and if you can get USD 1 in it by the end of next week I will send you $50 worth of the cryptocurrency of your choice.
PS Also I don't want to sound presumptuous but it seems to me you use the word "blockchain" as an equivalent to "bitcoin" or "cryptocurrency". It could be the case that some of the points in this type of discussion rely on the differences between those concepts.