The electoral college is relevant because, without it, cities would be dictating the politics of the entire nation. This is a typical US electoral map by county by county to see who won the 2016 election.
This is the same election results however it is displayed in 3-D.
As you can see, Los Angeles, Chicago, Miami as well as other major cities would determine the "nations" politics. This is what the Framers of the Constitution feared and created a "republic" allowing a voice for all.