The problem with your whole argument is that ultimately it comes down to the fact that the literal minority might be unhappy that they didn't get pick the winner over the will of the majority, and that might make them feel that it's exclusionary to them.

Such an outcome strengthens the “not my president” sentiment (on either side),

By definition, the majority will actually get their chosen candidate as president. Do you know what strengthens "not my president" sentiment? Having a privileged, autocratic minority choose the president, overriding the will of the voters.

Well, our campaigns are ridiculously antiquated with the campaign season being kicked off in....Iowa? And silly photo-ops of them eating county fair food and so on, as if that is somehow representative of America in the past several decades.

Sorry, most people are not farmers, and it's absurd to pretend as if that is "middle America".

It would make far more sense to kick things off on the coasts. Where all the people are.

As it stands, there’s this notion that a candidate has to try and have broad appeal; they need to spread their campaign out a bit in order to “capture” the electoral votes of a state.

That's currently not the case: in most states, the vote isn't close, so we know before the campaign even begins how most states will vote. There's no reason for Republicans to appeal to Kansans, because Kansas will vote R no matter what. Likewise, there's no point for Democrats to appeal to Kansans because it won't do them any good.

Sans the electoral college, I see presidential campaigns becoming even more polarized and exclusionary. The Democrat campaign will become the “big city loop.” Continually visit Los Angeles, San Francisco, Chicago, NYC, and Miami.

There's a word in politics for a candidate who wins in big cities, and nowhere else: "loser".

Check the demographics. Get a list of the 20 biggest cities in the US and add them up. You'll see that's only about 30% of the vote. So even if you somehow managed to get everyone in the big cities to vote for you, including children under 18, felons, and people on student visas, that still wouldn't be enough to determine the election.

Maybe they slide in a few secondary metros if it’s convenient. The candidate won’t have to worry about any non-urban messaging, and if they’re particularly incendiary could even preach “dumping those hicks in the sticks.”

Just in passing, there are more Republicans in the California sticks than the total population of several other states. If the president were elected by popular vote, candidates could no more ignore those voters than California gubernatorial candidates can, today.

I think it's a farfetched concern.

If you're still voting based on whether or not someone visited you or not I'm also giving you exactly 0 sympathy. It doesn't matter, that's just a show. Jason Aldean can visit all the county fairs he wants, that doesn't make him a real country boy or mean he's "with you." The same is true of a politician. What you should care about is how their policies affect you and the rest of the country.

Not to mention areas already have disproportionate representation via the Senate. If you can't get your case across to the majority of the county or by senate representation... maybe you don't have a very good case.

We should be trying to convince a majority of people about something, not forcing some arbitrary "win" that allows a minority to have disproportionate power over the majority in multiple areas of the country. We're closer than ever to having "taxation without representation" as is, and it's getting worse (Gore only had ~500,000 more votes, Clinton had ~3,000,000).

That's 3,000,000 people that didn't get their voices heard at all, and that Trump promptly told to go pound sand (even in the face of a natural disaster https://www.forbes.com/sites/alisondurkee/2020/10/16/trump-administration-refuses-to-give-california-federal-aid-for-wildfires/?sh=304cb4cb3416).