Sports are a game of our own invention, correct. However, they sat down and made specific rules for this single spectacle, aka a game of their invetion. That is categorically different, and that it is categorically different from marathon is my entire point.
On long distance running, you are correct I know a lot more about cycling and it seems every time I see anything about running discussions is, when people say that they don't want to become cycling with team captains and domestiques who get them water.
As opposed to the natural phenomenon of running through the streets of Berlin/NYC/Boston/Chicago/Tokyo as God intended?
All sports are a game of our own invention.
You are also incorrect about long distance running rules preventing teamwork. Marathoners definitely work together.