Seems like there's a good framework in place to catch up to the competition. I'd switch away from TinyMCE or Summernote if there was a component/widget system that worked well. Writing custom behavior for any HTML editor is painful, and none of them have a big use case in mind: custom layouts.
SiteOrigin's Page Builder for WordPress is cool: https://wordpress.org/plugins/siteorigin-panels/
I wanted something (Free or paid) like what's shown in the above video, that's independent of WordPress. Couldn't find a darn single one, if you can believe it. I'm stuck with Summernote + workarounds to get something similar for a Laravel project of mine.