In reply to Richard Ginn.

I asked the very same thing to Matt Mullenweg in person at WordCamp Miami and he replied with something I did not expect (no exact quote; but along the lines):

"Imagine they all were to use Gutenberg. If instead of the users having to get used to all of these builders. Have them united under one system. And then the companies who make these builders would create unique gutenblocks or otherwise contribute to the Gutenberg system to make it universally better for everyone."

And having met the man behind the vision definitely lifted my spirits and confidence in the project.