Why am i going against grampchamps and champs in casual?

I am usually between high diamond 1 to mid diamond 2 in ranked 2v2 and sometimes to warm up i play casual however i litterally can’t do anything as everyone im match made with isn’t in my rank. Casual was meant to be a fun way to play without worrying about your rank yet im being match made with mid champs and mid gcs. Is there a way to fix this?