From a data management and flexibility standpoint, I see why block editors are becoming popular with some people. But as a user, it feels like a downgraded experience.

When writing multi-paragraph prose, the first draft isn't always the final draft. Quite often there's some shuffling around of parts of the content. With blocks, the user can't highlight part of one paragraph and into part of the next one because of the artificial container boundary.

Perhaps with some well planned keyboard shortcuts and other UI improvements, the friction can be reduced. Maybe also it will require a change in the way some of us think about content (although I still object to the user needing to think of content in terms of its subtypes and storage structures).