Superman should come to blows with major corporations way more often. Think Omnicorp in Robocop (or most big ones today) corporations with 100% callousness when it comes to every day humans.
CEOs and boards of directors that make Lex Luthor wince. Withholding vital medications from the general public, creating giant Doomsday-esque creatures, Cadmus Labs having a whole subclass of mutated people living in the sewers of the City of Tomorrow, etc.