I'm sort-of leaving tech, but I've worked in web dev for 8 years, and this is the first I hear of Gutenberg.
From what I understand, it's better WYSIWYG. Great, but we have entire essays demonstrating how WYSIWYG is garbage. Alright but people want WYSIWYG!
To me, this seems like a manifestation of the limits inherent to the simplification of UI. The frontend needs complex information to be able to correctly produce a beautiful design. Ultimately, the user needs to be aware of the concepts (too complex, apparently), or the design needs to be automated and therefore simplistic. WYSIWYG is the unhappy compromise demonstrating that consistency begets complexity.
If this dilemma really is unsolvable, then Wordpress is but one of iteration in a grand cycle of its victims. I worked mainly with Drupal, and the situation there isn't much better, they've simply opted for sophistication over usability.