With National Popular Vote, every vote would be equal. Candidates would reallocate the money they raise to no longer ignore more than 2/3rds of the states and voters.
16% of Americans live in rural areas.
With National Popular Vote, big cities would not get all of candidates’ attention, much less control the outcome.
The population of the top five cities (New York, Los Angeles, Chicago, Houston and Philadelphia) is only 6% of the population of the United States and the population of the top 50 cities (going as far down as Arlington, TX) is only 19% of the population of the United States. Suburbs and exurbs often vote Republican.