Yes, it is true that there are SOME professors with chairs. Not that all professors have a chair. analog31 already explained this in response to your last comment.
The professors I’ve worked with usually only get that title when they have a couple of decades of experience and are at the very top of their fields with international recognition and will of course be funded and tenured. It sounds like you’re using ‘professor’ to mean something far more junior which is why we aren’t understanding each other.
> Meaning "office of a professor" (1816) is extended from the seat from which a professor lectures (mid-15c.).
https://www.etymonline.com/word/chair
Seems to be in-use in the US?
https://depts.washington.edu/givemed/prof-chair/creating-you...
It even talks about how the endowment for the professorship or chair funds the professor.