This person lives in the middle of nowhere to the extent that it's surprising that they have internet access. This person has never been near a city of more than 100,000 people and just watches TV nonstop while complaining about how horrible people are who live in different places and in different ways.
“You’re not a city until you hit 1m.” So what you’re saying is there are only 9 cities in the entire United States? I think you have your definitions wrong, or you live in New York / Los Angeles and have no clue what most of the US is like.
Worse: there are really only three cities in the US: NYC, San Fran, and Chicago. They are the only ones that meet the definition that people around the world accept as being a city. The rest of the US is just large towns unless you're going to argue that Omaha is like Paris somehow.
There is in fact no generally agreed uppon definition of a city. Most people would call Boston a city, but it only has 675k people. Most people wouldn’t call Wells a city, but the British do. Most people would call London a city, but not the British. Generally, a city is a defined area with more density than surrounding areas over 100,000 people, and a significant other factor, be it cultural, administrative, or historical.
On your second point, the US has nine cities over the 1 million mark according to the 2020 census. New York, Los Angeles, Chicago, Houston, Phoenix, San Diego, and Dallas. Boston is number 25 with 675k. Omaha is number 40.