Looking At Your Self
I absolutely believe that no human being is free from defects. So, finding ourselves disappointed with a fellow human being is simply inevitable. I recommend that we accept and embrace that reality.
Now, demanding the other person to change as a solution to your own pain? I'm afraid about how flawed or inadequate that strategy can be overall. It could be more an unconscious motivation for self than for the other person. Instead of facing the possible need to be the one who makes changes, the demand may actually be one's resistance to honest self-assessment.
Indeed, you should not set out to demand change from another person without your looking first in the mirror. Be aware of this need. You are going to run headlong into it anyway in your healing journey before things get better - individually and relationally.