As you say Justin, it’s good that you are accustomed to where everything is in FSE, but that just suugests that it really isn’t intuitive enough to users fresh to the experience.

I’ve returned regularly to Gutenberg on each release and trying to exit the theme editor is as confusing as I don’t know what? So far the only avenue is the back arrow 🔙 at the top of the templates list on the left: back, back, back till you teach the dashboard. Unless I’m missing something it all seems like a time wasting exercise.

I have been using the block editor in part, for post content, and for this task it is a brilliant replacement to the classic editor but, for everything thing else, relating to design and layout, I reach for my favourite page builder. I am agnostic about these builders, there are several good ones for people to chose from and there are some good block solutions too, if you are using something like Toolset. And, despite all that is being said, builders are keeping space of what is happening and are still ahead enough for people to use them… and this is the big mistake with the Gutenberg project, thinking it can blow everything else out of the water and create a unified system where fragmentation won’t happen anymore.

The big mistake here was not setting a restricted set of blocks for layout and elements., allowing only these to be overridden by third party plugins and page builders, Turn off any of these or switch to another and at least the general content would remain intact. As it is, we now have a smorgasbord of block suites all reinventing the wheel and none of the them interoperable.