In reply to Bastian.

I cannot count how many times I've asked for reference documentation for classes and containers to apply to my theme's block editor stylesheet. Trying to figure out the overloaded nested divs in the editor is a nightmare. Then there are many elements that no matter what you do to change the style, the core styles still cancel you out.

Trying to get the theme front-end styles to match in the editor is an ongoing issue.

There is also the problem of so many changes that happens with the "plugin" version of Gutenberg, that one has to design/develop a theme for several versions...and I've listed this before many times:

Classic Editor
Core Block Editor
Gutenberg plugin

Yes, three different environments to manage. Now, with what is coming, it just adds to the messy complications of adapting themes (new and old). How many more versions of the GB plugin will there be? Personally, the plugin needs to end and keep all GB development to the core.

I still say to this day...and have since the beginning of GB...Matt (Automattic) should have built a completely separate WordPress that is built around Gutenberg and then leave the original WP intact as the Classic WP. Yes, it means two WordPress versions, but due to the complexity and completely different concepts, they should have been separate.