tinyMCE was a walled garden. You could put any styles within that iframe and do whatever you want. Gutenberg is more open. It takes more care and forethought.
“You can enqueue them just like any other CSS file. Gutenberg will wrap the styles in an editor-styles wrapper and then you can use it.”
@WordCampLanc @erikteichmann By giving context in the editor it will become more apparent to person editing the page that a white image behind white text isn’t going to work and they shouldn’t publish the page like that.
(No one raises their hand)
Because every client asks “What is it [the content] actually going to look like?”
Who here has used the Gutenberg editor? (a lot less)
Who has developed a block? (not much)