In reply to chuck.

I've been thinking a lot about this and there's actually some precedent on how to handle this. Personally I always use the text editor in tinyMCE, so much that I often click the "Disable the visual editor when writing" option on the profile page. I think a similar solution could work. By default new installs get Gutenberg, but you have a profile option to use the legacy editor. Maybe even a global setting to set legacy for all new users (or even all users). Something along these lines is probably the closest we'll get to the best of both worlds.