In reply to mark k..
What do you mean the REST API was insignificant? The future of web is moving towards client side rendered web apps and without the REST API WP wouldn’t be able to follow this evolution. There are many great examples of how the REST API is being used. As an example I run a small webshop which uses a service that utilises the REST API for shipping allowing super easy integration without the need of an additional plugin. We’re also planning on using another service that utilises the REST API for automated accounting. It might not be that prevalent for many of the smaller WP sites right now but on an enterprise level it has had a huge effect.

As for Gutenberg I, for one, can certainly say it’ll revolutionize the way I build WP sites. I find myself constantly needing a user friendly block layout system and am currently using custom fields frameworks to achieve that. This doesn’t provide the best UX. Gutenberg offers a much more intuitive and easy way for the users to build their pages. I’m actually extremely impressed with how user friendly Gutenberg is. It is certainly much more intuitive and up to par than the post edit screen and TinyMCE are. If you look at other content publishing platforms all of them are using something similar to Gutenberg. It’s the future!