Being able to use multiple fonts, paragraphs and formatting on a singular word or sentence, within a single text box.
It would massively help for the times that you want to use the effects tool and have a couple of paragraphs of text within a transparent box. So that there are no seams or overlapping parts in your work.

The formatting and/or font variety can assist with having a title and a body of text within the same box too.
It’s a no brainier.