I've been an editor for 31 years and in high-tech editing for 20 years. My company does not allow me to revert to an earlier version of Word for security reasons. *sigh*
Here's a list – so far – of why Modern Comments are severely affecting productivity/work life for me as a high-tech editor:
1. Previously, comments were final once you hit the return key. They were also completely editable just by inserting your cursor. I spend a lot of time editing my comments in order to explain a style rule as clearly as possible or to soften my tone later. Now, I have to hover my mouse over the comment box until the word Edit appears, then click Edit, then actually edit my comment, then click Save. Multiply these extra steps exponentially, and you have a severe productivity issue.
2. Instead of being located in the right-hand margin with insertions and deletions, comments are now in their own margin to the right of insertions and deletions. This means that I have to shrink my page view in order to see them. I’m already on a 22-inch 4K external monitor, but I should not have to shrink the size of what I edit more that what is comfortable for my (aging) eyes. And if you have your view set too small to see the comments margin, Word doesn't jump you to the comment when you begin typing it. You're just typing the comment blind – off screen.
3. We use subscripts at my company for parameter symbols like voltage output (VOUT, with "out" subscripted) and input (VIN, with "in" subscripted), but I cannot superscript or subscript anything in these comments; it’s plain text only. If I’m communicating with an author about a parameter symbol, not expressing it properly makes me look less credible (when I’m already trying not to look dumb, because I’m editing an engineer's work but don’t have an engineering degree).
4. If you forget to hit the paper airplane icon to save a comment and try to open up a new comment, if you start trying to type your new comment, you’re doing so in the window of the comment you forgot to save. That comment could be several pages away from where you want to be. So now you've been jumped back to an open comment. Another issue impeding productivity.