Having only a single field for the entire name should be the norm all across the world. Automated systems can call people by their full name ("Hello, Bob Lemon").
It's gender neutral, solves sorting issues (e.g. Japanese), people without surnames (e.g. some African tribes, iirc) and whatnot.
This is nonsence though, they're making up nonsence to sell a nonsence argument.
They list a lot of countries and say they have naming conventions which aren't simple but they're ignoring the fact those countries have a legal requirement for a child to be given a legal name and that legal name can only be changed by official process - my tax software doesn't need to worry if your mom calls you squgglewoo written as a squiggle that's not your name
The article doesn't say that you must support all people's names, only that you should make fewer of the assumptions (not even none)