I've spent the better part of today experimenting with full site editing. I've worked through Carolina Nymark's fullsiteediting.com course, which I recommend to everyone who's interested in this subject.

Clearly "fse" has come a long way since I first looked at it earlier this year. I like the idea of block-patterns as design bases, global designs, and sure, let end users play around with the blocks on their pages. Most won't want to do it anyway - but patterns instead of shortcodes, sure, that's a better solution.

That said - at the end of the day of perusing the fse course, after swapping template parts in-and-out, I still wasn't able to position the website-title block next to the website-subtitle-block with the distance I wanted (within a columns block). I wasn't able to place a menu on top of a cover block and position it properly. Basically, I wasn't able to do a lot of the things that I wanted to do. And many of those need to be done in a lot of themes.

Just as in Gutenberg "for posts and pages", basic positioning of elements is, in my experience, just not working as at least I expect it to work out of the box. I don't like Elementor, but it's working intuitively in a way Gutenberg still does not. In Elementor, it's possible to properly position elements within sections using CSS values in option fields in ways that are hard to find in Gutenberg, although some additional controls have recently been addd and some more are provided by plugins. That may not be too much of a problem for most posts and pages while displayed within a theme, albeit annoying, for sure, but for fse it is really debilitating if this is not provided in the core.

In general, I find it difficult to understand which parts of the fse theme are now supposed to be styled completely through their blocks and which parts will still require additional styling from the theme's stylesheet, or what the expected interaction between those elements will be?

I mean, take the positioning of the search field and button in the screen shot of the template parts above. I'd say they need to be pushed down a couple of pixels to sit right in the black bar. Would this have to be done through custom classes added to the block and added to the front end through theme.css? Or should this be done in the editor? I would expect this to be possible in the site editor for an fse theme, but currently at least, it isn't.

I understand that fse is the way WordPress as a platform is going quickly, at least philosophically. Practically it will take a lot longer. While I try to keep up with what's going on, I can't see myself recommending an fse based theme to any client anytime soon.

You're right that many clients now expect sites to be up and running faster than before, and part of that expecatation is the kind of visual templates for various systems you refer to. But so far, fse isn't really a way to cater to that expectation.

It will be interesting to follow the development this year, and hopefully, some of my questions will be answered and some of my problems will be solevd along the way. But today, sadly, I can't say that I share your enthusiasm.