This is a flagrant lie. Batman does not "get as good as he gives" by any stretch of the imagination. Not in exposure, treatment, or literally any metric you could possibly describe. The crushing majority of the time Batman gets the best of everyone. When it's the reverse it's a rare occasion and usually shortlived.
For instance, let me put it this way. What Batman has been doing to everyone for years is what Harley Quinn did to Batman (and Superman and Wonder Woman) in Heroes in Crisis. And boy howdy did every Batman fan get annoyed at how stupid and awful that scene was. How dare a super popular character make Batman look like a fool and beat him when it made no sense! This may not have been you, but it was certainly a big deal when it happened, spearheaded by Batman fans.
Ostensibly, Batman appears in the most comics because his popularity will garner attention and sales. If the end point, bottom line, pure capitalistic motive is the case then there's a lot of dissonance in simultaneously having Batman make other characters look intentionally less appealing, because that hurts that other brand's chance at succeeding without Batman.