If a majority isn’t a majority then what is it?
What if, in your scenario, millions lived in that one city and the boonies, all put together, amounted to a dozen, total. What gives those people more of a voice than a dozen in the city? Just because people live in a city, doesn’t mean they all think alike or want the same things.
If the people want a cat, they’ll elect a cat. Whether there’s an electoral college system in place wouldn’t change that. There’s nothing about cats that’s going to make everybody in the cities vote for it and no one in the boonies.
Yes there are more liberals in the cities, but if liberal candidates started pandering to only those in the cities they would lose a lot of other votes fast. As is, we have conservative candidates who don’t consider those in cities at all because they don’t have to (well besides corporate fat cats). Our current system gears elections to a small amount of states, not the whole country. Why should people in the rust belt and Florida have control over the country?