As a French person who grew up going to a school in Belgium for a bit as a kid, I was quite amused by their numbers.
My thought as a 6 year old was "aw, are soixante-dix, quatre-vingt, and quatre-vingt-dix too complicated for you?"
Even now, while I think the French numbers make objectively no sense (even the countries that do count in 20s are at least more consistent than us), I can't help but find the Swiss and Belgian numbers "cute". Like "Baby's first 70 to 99".
And for whatever reason, I don't have the same opinion about 70-99 in English, Portuguese or Spanish.
Edit: just to be clear, I think my thoughts about it are absurd but they're too deeply engrained and decades old to shed completely.
It’s a well-known phenomenon that with the internet and modern media, large countries’ version of a language can affect the speech of the smaller countries using that language. Think kids in Portugal today growing up using lots of Brazilian words to their parents’ dismay, or americanisms slipping into UK speech. This makes me wonder if any young Vallon French speakers have started to pick up standard French higher numerals.
1999 == One thousand, nine hundreds, four twenties, ten, nine.
I studied French in grade school over ten years and I love it. But the way numbers convert into language is wild. I tease it with love.