Banks and firms that uses their services are audited thoug. It is not blind trust. And regadress the tech used there would sitll be audits.

You dont need 51% attack to corrupt a ledger. Just enter incorrect info and the ledger is wrong. Not a damn thing a blockchain can do about that. Same issue is with any trustless system where you have to trust someone to input the correct info/do the agreed thing/ship the ordered physical item.

Using comma would probably caused more problems as it is a decimal separator for those languages. My excel also uses semicolon in formulas instead of comma when separating parameters. Some VBA scripts break when using different language settings and some forumilas don’t translate automatically to different locale so they just give an error. Overall using excel in different locale setups is annoying.

Best separator I have used is | as i have never seen it in the data as an input. Comma and semicolon both have caused issues in the past for me as they might pop up at wrong places.

With crypto you face similar problems. You need an address, waiting is shortr, rugpulls and other scams are one of the biggest use cases so getting crypto stolen seems common. You might be able to verify that crypto was revceved but as with any trustless paymet solutions the issue is that getting the item you ordered is the part where trust is needed the most. Good luck asking back money when you get an empty box.

You can cross over Finland from that list. Maybe more as that was only i checed and you were wrong.