What about when you use only SSO for authentication?
It’s one of discourse features to disallow email logins and allow SSO as your only authentication system.
You can set both “enable local logins” && “enable local logins via email” to false.
As well as “disable emails” to “yes”.
Maybe it wouldn’t work as a standalone product on its own, but it can as a part of a bigger system. Also, if that was true, “discourse cannot work without email”, why would you have all these settings to break the system?
“That banner is there because it’s telling everyone that the site is broken.”
Again, I don’t think “everyone” needs to know.
At least in my opinion, only the staff or admin needs to know. Not the consumers of the product.
Btw, that’s how we’re using it. We have a main website where you do your login/logout/register/reset password, etc.
The only way to get to discourse is via SSO. That way we can easily provision permissions via groups.