I'm an active core-contributor to WordPress, and I maintain a core component (Privacy) currently.
Even within the core-contributor community, there is a lot of friction, particularly with the "less popular" components. Accessibility was the first to snap, with the lead resigning, but not after other big contributors took long breaks when needed most. BDFL Matt hasn't helped heal the fractures and has hurt even more components since. The Privacy component, for example, was the butt of a joke during his WordCamp Europe keynote, boiling down our efforts over the past year as asking users to take cookies, which hurt Privacy team morale (the Privacy team primarily worked on creating a standardized way in the core to identify and export personal data, and help people create Privacy Policies by standardizing how plugins can identify what data they collect).
The largest issue is React -- it's so different than the rest of the WordPress core, that 90% of the core developers can't work on Gutenberg issues. WordPress is primarily PHP, and if JS is used, most places jQuery is the framework of choice. It's dated, but it works quite well still. React is quite the departure from all of those technologies, and will cause gigantic rifts in the community. I do believe WordPress will survive, but with thousands of plugins lost forever due to lack of updating.
Component approach is good, but why force everyone to use React or any particular framework? Wouldn't it be better to implement this as vanilla js component? Either via web component or just plain custom element.
Nowdays there are some really good solutions like quillJS or prosemirror that are not tied to particular solutions.
Even if they were to make the default theme based on React, nobody is using it. Everyone switch to something else right after install.
Should they change the entire stack to use React, they would lose a lot of their community. A lot of their users are code novices that make do with simple HTML and some PHP snippets.
"Wouldn't it be better to implement this as vanilla js component?"
I have not yet done this, but as I understand it... it's possible to use whatever JS you want as long as it works with the GB api.
Basically, I did the hello world react Gutenberg thing, then took a look at a11y and saw that none of the 8K or so institutional user I support could probably legally use it, and then got back to whatever Vue map searching for CPTs or whatever BS I was building based on ACF and plain old CPTs.
So I dunno for sure, but as I understand it you can build your Gutenberg components in any JS-based system without a lot of overhead. But of course, probably best to just use React as that is what all the core components will be written with.
React is a library and can be used as a thin layer over plain JS. It's just often not used that way.
As with all libraries, you still have to be good at organizing your code for it to help you in the long-run. That's a lot of the appeal (and problem) of full frameworks: it decides how to organize your code for you.
Even within the core-contributor community, there is a lot of friction, particularly with the "less popular" components. Accessibility was the first to snap, with the lead resigning, but not after other big contributors took long breaks when needed most. BDFL Matt hasn't helped heal the fractures and has hurt even more components since. The Privacy component, for example, was the butt of a joke during his WordCamp Europe keynote, boiling down our efforts over the past year as asking users to take cookies, which hurt Privacy team morale (the Privacy team primarily worked on creating a standardized way in the core to identify and export personal data, and help people create Privacy Policies by standardizing how plugins can identify what data they collect).
The largest issue is React -- it's so different than the rest of the WordPress core, that 90% of the core developers can't work on Gutenberg issues. WordPress is primarily PHP, and if JS is used, most places jQuery is the framework of choice. It's dated, but it works quite well still. React is quite the departure from all of those technologies, and will cause gigantic rifts in the community. I do believe WordPress will survive, but with thousands of plugins lost forever due to lack of updating.