Doesn't Congress Have Better Things to Do?

Congress continued its fascination with the District of Columbia's gun laws with the House of Representatives passing an amendment in a federal subsidy bill for DC that will allow DC residents to carry loaded pre-1976 handguns and rifles in their homes. As I stated in an earlier post, I do not support DC's ban on handguns, but any change in DC's gun laws should come from the DC government and not the federal government. Now I've seen the argument that Congress should be actively trying to repeal DC's gun laws because DC's gun laws violate the Second Amendment. If that is what Congress's true intention is, then why don't they introduce a bill than bans states and local governments from enforcing bans on handguns. DC is not the only local government with strict gun laws. The City of Chicago bans handguns. Why doesn't Congress prevent Chicago from enforcing a ban on handguns if they are so concerned about upholding the Second Amendment. This is just another example of Congress's increasing desire to further reduce federalism and act as a superlegislature.