WP is unusable without this, or similar, plugin

The “new” editor, which is years old now, is utterly useless. You simply can’t even use WP with that default editor – it boggles the mind that it continues to exist.

If you want to actually USE your WordPress website, you have to install this plugin. Or one of a number of other plugins that does something similar. The non-existence of this table-stakes functionality in a default WP install causes one to seriously wonder about the mental stability of the WP development staff.