Seems like every character and their sister can fight like a ninja and cause major problems to proven powerhouses these days. I guess showing a z-rate villain smack around an a-rate hero they gain some comicbook credibility, right?
I don't think so. I think that really you are undermining the a-lister's standing which in turn damages your properties as a whole.
A character, like Robin, should have to fight tooth and nail to keep up with even a relaxed Batman otherwise, why have him at all?
Robin is learning (all be it for forty years! ;) ) But Batman on his worse day would run rings around Robin on his best.
Robin is a more relatable character in a battle, Batman would seeingly take down a crowd of assailants effortlessly, we can see that effort, luck and persistance are Robin's key cards in his deck and that is far more relatable. This provides us with a stepping stone. From us, to Robin, to Batman and that is a product booster. Where-as if Robin could match Batman, well that undermines him.