In reply to John.

> What about the people who will never be ready to make that change and don’t want to hear anything about Gutenberg, ever?

You should install the Classic Editor plugin, which will keep the current editor as the default when WordPress 5.0 is released, which will include the Gutenberg block editor.

The Classic Editor plugin will continue to be maintained into the future, so you can continue to upgrade your WordPress install, and keep your current editor.