Our society tends to underestimate the importance and fortitude of sidekicks due to the preeminence of the alpha dog.
It’s not even a dichotomy that gets thrust upon us, because sidekicks have the same objectives as alpha dogs when approaching the task at hand.
You’re not choosing amongst the two of them, because they’re on the same side. It’s not a hero/villain dynamic.
The perception with sidekicks is that they’re present only to provide the alpha dog with support when they need it, instead of adding their own flair to conquering the given situation.
Batman might be the ceremonial “leader” of the duo, and while Robin certainly can’t do everything that Batman does, it’s equally true that Batman can’t replicate Robin’s unique talents.