Système international? We already use french units

No, 'international' does not mean 'French'. Yes, the French came up with it but since it now has international adoption it is the international standard with the United States as one of the last hold-outs. That's what you get when you have a country run by lawyers with very limited input from science.

Inches are in fact an international standard to which multiple nations have formally agreed

https://en.wikipedia.org/wiki/International_yard_and_pound

You'll notice that they are defined in terms of SI units.

I do notice

The metric system is decidedly biased in favor of languages that use 10^3 prefixes as opposed to 10^4 prefixes or 10^5 prefixes.

Uhhh why France?

Within the EU France is quite nationalist compared to others, and yet, I fail to imagine someone there producing something like this. I'm a bit allergic to flag waving.

Ah, I interpreted it as a comment on the difficulty of creating the national flags in pure CSS.

The French one, in that case would seem trivial in comparison.

Hence the reason for my original comment.