What do you think doesn't belong in Unicode? It turns out that expressing all the different ways humans have used text in history has some necessary complexity, but assigning each character and modifier a number seems like a perfectly reasonable approach.
"have used text in history"
That's how Unicode started but nowadays Unicode expresses things that are only used because Unicode itself introduced them.
And this while many important things in the "have used text in history" category have been unfinished or not tackled at all.