This function of the Senate is IMO far more important than arbitrarily giving group A of citizens multiple times more political power than group B. Equal representation of states was conceived of in a time when our nation was very different. The Senate's current form was an acknowledgement of the fact that each state was sovereign. The framing of our Constitution almost bears more similarity to the EU than it does to the US that we recognize today, at least with respect to the attitudes towards the relative independence of each state.
On top of that, the divisions that made a "state" anything more than an arbitrary administrative division based on an accident of history are largely gone. The urban-rural divide is far more of a dividing line in terms of demography and ideology than state lines are. Citizens of Los Angeles and Richmond, VA are far more similar to each other than they are to citizens of Shasta County, CA or Wythe County, VA. Just look at any per-county electoral map if you don't believe me.
This map, or something like it, preserves all the benefits of the Senate while going a long way to fix what's horribly broken about it: namely, granting huge amounts of political power to arbitrary blocks of citizens.