While I enjoy page-building with third-party block sets (but not the useless core and Gutenberg plugin blocks), I'm just wondering why Automattic didn't think of expanding on the customizer instead. It's UX is infinitely better than the block editor. And themes such as Neve, Suki, Customify, and Blocksy have amazing header and footer builders.

(Fun fact: Neve's header/footer builder actually mimics Gutenberg.)

Automattic had a good thing going when it was moving everything (like widgets and menus) to the customizer. Neve and Suki themes even have their page header options in the customizer so you can see your changes happening as you do them. Themes like Colibri WP and Mesmerize turned the customizer into all out page builders.

Automattic could've turned the customizer into an open source page builder.

Unlike Gutenberg, you can actually see your website as it is in the customizer, and you can see your changes instantly without opening a new tab and refreshing every five seconds like the old primitive way.

It would be a real shame if the customizer goes.

Gutenberg's narrow document-like view cannot serve as a replacement for the customizer. It just can't.

It's only good for writing blog posts. That's it.

Here's an idea. I think the customizer should be merged with the block editor. When you add a new page (not post), you should see your whole website as it is (not the narrow document view). The left side dashboard menu should be gone (I disabled it but there's still this document view).

On the right side menu, when you click on the future "Global" tab, it would be the customizer. So the customizer would be on the right side instead of the left. Or maybe the whole menu would be moved to the left side.

Only when you add a new blog post should you see this narrow document view in the block editor, because now you should be concentrating on writing your article only.

If this narrow view is to be kept, then the entire website must be displayed in it, but with everything shrunk. Like in Oxygen. I think Webflow is like this too, but I'm not sure.

These are my thoughts.