I feel that modern browsers lack the feature to “Discuss/comment on a page” with the ability to edit, comment, and review anything on it, contextually and multimedia-wise. Yes, it would require a smart system that remembers where edits were made, so that changes in the page do not lead to issues with linking the comment to a specific place, etc., but this is not very complex, and it is normal that it might not work on some systems (like SPA). On desktops, screens are becoming larger than what browsers need, and having an additional hideable panel for discussions, remarks would be simply invaluable. Wikipedia could be adapted for this purpose. I mean, the same idea: anyone can change another’s edits, but the latter will receive a notification, and can revert the edit, while the page author is just another participant.
Hi, I'm Rauf Aliev. 