Andrzej, Thanks for taking the time for such a thorough response, and it deserves a response. First, I would highly recommend you read a book called Finite and Infinite Games, by James Carse (not the Simon Sinek one inspired by it). It will give you a clear perspective on the difference between destructive and constructive "games", which you correctly point out to be a common human activity. Carse is the godfather of the so-called Game B movement, and his book, written in 1986, has led to countless developments in 'game theory', which seems to be of interest to you.
Bottom line: games you play to win pull people down, while games you play to continue lift people up. Of course that's an oversimplification.
Another way of looking at it is this: New Zealander Niki Harré's research led to an "infinite values" word cloud. What's amazing is that one cannot construe a losing outcome from any word therein; whereas those in her "finite value" word cloud invariably lead to losers.
Infiinite players build the world. Finite players destroy it.
I wrote a piece on the subject here: https://anthonyfieldman.medium.com/finite-and-infinite-players-d47bd9210ff3
The 'credo' you reference is no more than a call to act on the better angels of your nature. Unless you think Lincoln was a whacko, there's a reason these words in his inaugural address have been replayed for 150 years. We have it in us. If you're a parent (I don't know) you do this continually with your own children. You don't "screw them over" to play a game that will destroy their lives. It's against your own interest. Same with B-Corps, Co-operatives, and other "real business" typologies that exist, if admittedly not too much in the United States. On that topic, the Nordic Model stands as the world's leading "ism" with regard to human prosperity, in the "real world", leading to the highest per capita incomes, innovation centers, and the world's happiest people. What a concept. I wrote about it at length here, if you're interested: https://anthonyfieldman.medium.com/northern-lights-748f8ef9c0ee
The only other leading example I can give you for how this works in real life is a mega-cooperative named Mondragón in Spain—the nation's most profitable business sector, operating since Franco's time—so over 80 years now, and numbering over 85,000 innovative individuals and companies who run their own banks, schools, food systems, etc. It was built on a relationship economy. I wrote a piece for The Startup on that, too, here: https://medium.com/swlh/the-relationship-economy-5e9bab6f7ce5
Thanks again for your thorough provocation. I really appreciate your perspective.