Because you mentioned the Super Bowl comment which I know I said. We have beaten the Titans, Vikings and Jags...all very meh defenses though the Vikings is at least a tough scheme. This upcoming game against the Rams will be an actual test to see how he elevates his game vs top competition. At that point, if he balls out, you can justifiably argue that he has proven he can take the Cardinals to the Super Bowl as he has beaten a Super Bowl contending team.
I don't think a single game encapsulates proof one way or another. Heck the year Warner took us to the Super Bowl he had that giant stinker against the Eagles on Thanksgiving.
If he stays above 70% completion percentage and 9 yards an attempt then he isn't remotely the reason we don't reach a super bowl. That's Drew Brees level performance. Brees was never the reason his teams didn't participate in the super bowl.