I've seen this coutless times, and as a french native I'm getting tired of this, I want to tell you that no french think of it that way.
You know how you have "eleven" "twelve" and then you switch to "xxteen" for the next 6 number ? You never dissociate them, because that's just the way it is. French are the same "douze", "treize".... and then suddenly "dix-sept" but nobody dissociate them, this is just one word that means "17"
And then it's the same with "seventy", french don't dissociate 60 and 10 in their mind, it's just one word. Sure from an ethymologic standpoint it comes from two word but it's not how we think about it.
When you say "sunday" you never think "day of the sun", when you say "blueberry", "blackberry" you don't think of the color, you think of the particular fruit, everybody can see the origin of the word, but nonetheless the word is one unit.
Anyway. Yes it is weird to learn a new language and see how it evolved into a weird mess, but please know that when you make this kind of comment you don't look like you are well informed about the french language, you just look like kids that have learned a new word and can't stop using it everywhere.
I want to tell you that no french think of it that way.
Of course not, that's the point though. It is your first language, so for you that's the norm. But for the rest of the world with another language that's weird as fuck.
Not particularly offended, but just tired of seeing this jokes which I think is not really accurate, and it's like an entry level joke about french language, there could be so many ways to make fun of french