Eating out in US or any developed western civilization is so expensive that everyone in those civilizations think cooking is a basic skill.

I don't understand why there is no good cheap option. In Japan, I could go to a low-tier shop. It would cost $1-3; the food is decent with taste, and it fills my stomach. In US, $1-3 would be the min amount of tips.

Restaurants / cafes in Japan have less fixed cost overhead than in the US. Zoning, licensing, insuring, etc. in Japan are more conductive to small shops being able to stay afloat with only moderate business. There’s other factors of course, but those are biggest ones I found when exploring potential for small side project. With that said, I have yet to run a bar/cafe in either country, so my experience is limited to my research.

I think cooking is a basic skill for self sufficiency, if things go wrong in society.

Living in dense cities it can be easy to forget how many dependencies you rely on, it's a complex chain of logistics.

But I sure do miss the convenience and cost of Japan. Cities in Japan feel like they are made for people to live mostly outside of their house. Whereas it is so expensive to do normal city stuff in many western cities, it costs too much to participate every day.

I suspect it is to do with the amount of pedestrian traffic passing through an area. When you have a high population density there is an increased amount of foot traffic in the area you can charge less per individual serving because you have a higher overall volume of traffic.

Where I live in Australia the cheapest food tends to be Kebabs which congregate around pubs. There is a high amount of students walking (stumbling) home after a night out etc so they can afford to be cheap since they get so much foot traffic coming through.

My uneducated guess would be that rent and labor are much cheaper (in relative terms) in Japan than in the US, perhaps so extremely that it dominates compared to the marginal cost of producing food.

For starters, $1–$3 probably wouldn't cover the ingredients for most dishes. A single bell pepper, for example, is ≈$2. Ground beef for 1 is ≈$4.

… I, and everyone I know, can cook? Do cook. There's no way to eat out every night…?

The only place with cheap restaurants in the US is ironically NYC. The second most expensive metro in the country is able to sustain the dollar slice because of massive foot traffic. When you serve 100+ people an hour you can lower margins, and labor is a lower percentage of costs. Restaurants outside new york either have much lower sales volume or are corporatized and make massive profit.