I appear to be a dissenting voice on this, but I think Gutenberg is a remarkable accomplishment and a great editor. (I say this as someone who is actively developing an editor for my own app.)

It's a drastic shift from how Wordpress has traditionally worked, but that doesn't make it bad.

Most WP visual editors / page builders are terrible. They produce bloated code, huge page sizes, poor SEO. Gutenberg does all this stuff right. But it doesn't try to be a full-fledged design environment either.

The shift is painful, of course. It's incompatible with many existing sites. But I compare this to Apple's shift to OS X, or Microsoft's move away from Windows XP, or any major tech company that has had to shift away from a wildly successful product lest they become irrelevant. The transition sucks at the time, but looking back it always becomes obvious how necessary the shift was.