i like how people don't realize how far he's pushed himself as a human. here's a guy who can flying kick nearly 25 feet, in a heavy suit of armor. he's a cunning tactician, higher than an olympic athlete, and a literal ninja. LBSH if meta-humans didn't exist everyone in his universe would have thought he was a godlike monster. he made criminals believe this, and this is why the rest of the JL has respect for him. i think they respect him also because his power wasn't bestowed upon him, he earned it. so it doesn't mater if he can beat them, because deep down they know if they weren't gifted with their powers, who would come on top. Also the JL needs him as an ambassador for the human race. with out all the regular guys in the JL im pretty sure people wouldn't feel secure.
The Justice League needs Batman more than he needs the Justice League.