Population density of South Korea is very high. To compare with Canada, the population of South Korea is about 140% of the Canada's, but land area of Korea is just 1% of Canada's. In addition, mountains cover about 70% of the land area surface. I think that these high population density causes the Korean delivery culture. In Korea, you can get delivery food all the time. Through food delivery app like baemin or coopang eats, you can order variety of foods. If you want to get ingredients for tomorrow breakfast, order them at online grocery store and then you will receive it by next early morning. You can get some delivery food even though you are not in a building but in the park or by the beach.