To me, the most frustrating thing about the block editor, no matter where it’s implemented, is that it conflates content entry with design. I like to be able to just dump all of my content (if it’s prewritten), or type the content in, and only THEN start marking it up for styling. The block editor discourages this and almost forces a block by block entry approach. When I’m entering content I want that to be sole focus. Once the content has been entered then it’s time to style. Doing both simultaneously makes no sense to me.