It’s not needless pedantry. Calling it CSS is using a crescent wrench as a hammer and calling it a hammer (a running joke on r/tools). You’ve missed the entire point and someone needs to remind you - and everyone listening in - what the point was.
We had in-line style before we had CSS. We are going back and nobody remembers why we’ve had CSS for twenty years? Read some history.
We're not in 2003, though. If you're working on a project with somebody and you insist they refrain from calling the contents of a style attribute CSS because it wasn't always technically CSS, nobody will thank you.
Edit: actually, even when I was working with CSS in 2003 (IIRC, we absolutely were using separate CSS files then), this attitude would have been unhelpful, to say the least.
We had in-line style before we had CSS. We are going back and nobody remembers why we’ve had CSS for twenty years? Read some history.