In the long legacy of idiotic interface decisions by Microsoft, "Modern Comments" rates right alongside Clippy with respect to uselessness. As literally hundreds of comments on multiple sites indicate, most folks don't use comments to carry on chats, nor do we want that "functionality" at the expense of absurd layout issues and wasted document margin and visual display space. There are far better tools for chatting than this crap feature. Heck, even Teams is better for that purpose.
I'm now moving to LibreOffice for all of my commenting on both student and colleague files. Yes, it's a minor hassle to play file conversion issues. But it beats having to use this absurd re-interpretation of how people want to work on and with documents.
How about focusing some attention on things that actually need update – such as the bloated ribbon interface that has come to resemble a Frankenstein-like assemblage that can't be pruned or customized by users?