i don't follow the comics but things that are established that i know of are:
Bruce Wayne is insanely wealthy
Uses his wealth for his bat-themed middle age crisis (bat sports car, bat private jet, bat motorcycle, bat gondola probably)
Other than that the best thing he does for other people is "philanthropy" (in the real world this is a scam by the wealthy) unless you count taking in his young lover sidekick
The police and the politicians are extremely corrupt and are for sale.
Now from all this i gather it would be very easy for Bruce to get actual political power in Gotham to make real change but he doesn't do it because running around in a furry costume is more fun.
Even apart from that, sneaking around in a costume talking about how you're the night or the knight or whatever is on its own very cringe and psychotic.