After seeing the movie, it feels to me that this is more of a Batman movie guest starring Superman than a Superman/Batman movie. The titular fight between the two was quite underwhelming for me too, in fact, it didn't even need to happen, Superman didn't want to fight, but after passing through 2 traps (the sonic and machine gun traps which he could have seen from a mile away) he was gladly bashing batman through buildings instead of flying at a distance and trying to talk to batman reasonably.
What's worse, as I feared, they made him too weak that he got his ass handed over to him, the fight was pretty one-sided. I know they gave him some moments, but really with how the fight turned out, they didn't show enough of him at least controlling his strength, hesitant to fight (maybe even trying to talk to batman while blocking his punches), but could easily toy around with batman at will. He could've easily disabled batman and talk him out of it. Getting gassed the first time was ok, he didn't know batman had kryptonite gas, but twice in one fight? This certainly doesn't look like the Superman that went toe to toe with Zod, Faora, or the other kryptonians in MOS.