So the second movie undoes the achievements of the first (keep in mind that Bruce doesn't fight crime per se; he fights for Gotham, which is a different endeavor), and leaves in its place the shaky foundations of a disgraced vigilante, a dead DA, and a cover up. And now, besides Gotham's corruption itself, he has to fight the Joker, an active force of chaos.
Thinking in terms of a trilogy, the third movie is when Bruce wins. But he can't use Batman to win; at best, Batman can keep Gotham physically (and relatively) safe, but he can't change the tide of decay. The criminals he takes down are replaced by others, often nastier. What would work for me (but let's face it, because it's my favorite fan-fictional kink), is for Bruce to become what Gotham needs. Assuming he can, which is arguable. If he can't, then he already has lost, and he and Gotham are doomed.