Why is demanding independence not a diplomatic play?

[I got 1984'd]

It's either the overlord refuses it or they don't. Except, they will NEVER EVER accept it whatsoever, no matter how great your relation is with the overlord. So why is demanding independence even in the game? Is this an appendix of a feature?

[kgkong]

Demanding Independence is an action if your relationship is high enough with your overlord. There are other mechanics at play, you hover over the thumbs down to see what's holding you back from them agreeing.

The other way, is you expel diplomats and damage relationship until you are able to declare a war of independence as a diplomatic play.

[Kimlin]

Or you can use it as a counter war goal if your overlord gets ballsy and tries to annex you.

[I got 1984'd]

Ah I see thank you