This is Awful

Out of the box with no built-in fallback (classic as a plugin doesn’t count), this monstrosity turned re-wording an identical section of text on dozens of posts and pages created with other editors into a several hours long nightmare of restorations as other authors and contributors were also accidentally deleting a random amount of existing content with every save and update action. Had I known what the cause was earlier I would have restored a full site backup, but as it was I was just getting reports from end users of missing or broken posts and repairing them as they came in. It didn’t click until I started to get reports of things I previously restored being broken again (like after an author recreated his changes and saved again) and finally when the items I had changed were also coming in. Eventually, I had to disable all non-admin accounts to stop the bleeding and restore posts.

I finally tried merely opening and saving an existing item which resulted in random deletions of content from the item. Yes random. I copied the existing body in classic to the clpbrd, opened then saved without making changes. Everything past a random line would just vanish from the post. I then opened the post again in classic, pasted it back, saved, and again opened and saved in Gutenberg. Everything below a different line was deleted, and so on… 1 star is 2 stars too many to give this mangled mass of pain.