I will disagree with you here. I think you are missing an important aspect of comparing a popular state vote to a popular country vote. Most states have 1 - 3 major population centers. There’s enough time to campaign every where. In a country wide vote that’s not the case.
You hit LA, NYC, Dallas, Chicago, Detroit, Boston, Denver, Las Vegas, S.F, Miami, Orlando, Atlanta, SLC, KC, Baltimore, DC... and on and on ... no time to hit small pop areas. Hell even medium pop centers would see less love I think. It’s just buying the most bang for your buck in the time you have. We some limiting of that now because each candidate can ignore large parts of the country.