It's not technically required, but pragmatically, if you want to clear the content, you pretty much need a static. Pugs just don't clear T9 and even T6 is a toss up.

Statics can be great if you have friends you like playing with that much, want a sense of comradarie, etc etc. But when you can only clear the content with 1 group of people, a static may not be required de jure, but de facto, well....