Not sure if you've worked in an office recently, but on google workspace I (we) use very regularly:

- Group Editing - this ones hard to get right - Reviewing Tools - Automated document generation - Embedding of data-backed images from 3rd party tools

Looking at my wife who works in government, they use it even more heavily, with a lot of complicated formatting, numbering, standards etc going into each document, plus OneDrive collaborative features on top of that.

I suspect office-user people are where most of the features get used. Agreed, most people only use 15% of the features, but which 15% that is likely changes quickly person to person.

It doesn't need to be "most". "Some" or even "a few" can be enough to make a hell of a mess if those few have created documents that are key to the business in one way or another (proposals, end-user documentation, etc). And there are the other components to the suite like Powerpoint, Excel, and Project to consider.