Indeed, 5.3 has quit nice improvements for Gutenberg. Although it would take another 3 to 5 versions to level the UX of (for example) Elementor.
I can't deny the fact that Gutenberg created a gap for Elementor to even grow faster. I work with a lot of (young) marketeers and DIY-website owners, they mostly all grab to Elementor for new websites.
(so, yes WP is already an operating system... for Elementor)

Okay, you can use 'blocks' (just another other word for plugins).
And there's the upcoming block directory...

But what about block durability or higher risk on potential abandonned plugins/blocks?
What about loading times?
What does the plugin/block really do/load?

Cause we all call them 'blocks'; but they are just plugins. And most of them will have an impact on frontend. (js, css).
And we all learned not to install too much plugins, right.
But for blocks; it seems no issue.

Those are the questions i have in this momentum building new custom sites. I'm not that keen relying too much on third parties blocks, i prefer to rely on core to create durable sites for my customers.

That's why i hope the development speeds up like 3x faster for core.