The accessibility concerns are well covered but the usability of this thing is still very odd. The interface doesn't give the key block actions the prominence required.
I've been testing Gutenberg since the start of its development and in my most recent tests I confess I have no real idea how to delete a block from a page layout! I guess the little bin was removed recently.

As a relatively competent user I know I can click a block and then in its text-formatting bar I can click the 3 mysterious vertical dots and at the bottom of that resultant contextual menu select the "remove block" option, but that seems too buried to be the real primary method. Also the keyboard shortcut suggested is "shift alt Z" which is surely not anyones idea of a delete-block shortcut. I'd have guessed at "shift-del"

Also, another example of the strange interface:

The most important button to introduc to users is probably the new "add a block" button, but it's a pale grey 15px mysterious + icon tucked up away in the top left. Completely anonymous. If the Add Block menu is found ... this should now be the showcase of the new editors abilities, the grand presentation of the glorious new features. Look at the sidebars of Divi or Elementor. They lay out their wares. Meanwhile the Gutenberg block display ... It's about 300px high! A cramped, nervous, mysterious, awkward little thing. It's nearly imposible to investigate potential through this tiny little scrollign window. Why is this not a glorious display with a height:90vh? Why is it so small? For what reason?

That's just two observations of about a hundred. I know I may as well throw these down a hole for all the good they'll do - but as end users start to discover this interface they will be very underwhelmed.

I agree with everything David Innes said earlier, in the first five minutes most users will not be excited and seduced by this UI introduction to the block metaphor.