A software development team probably shouldn't be a "one person wins, everyone else loses" scenario, though.

The ideal "10x engineer" in my mind is one that helps their team win significantly more often. Competitive swimming is maybe not the best analogy (although I have worked with engineers like that before too). If you want sports, maybe basketball. You've got a good team, but you've got a stellar player that makes them all better.

well to simplify it: if 2 competing companies with 1 programmer each were trying to create $popular_app_or_website then the company with the more productive developer would "win" more often

no, businesses win or lose based on sales & marketing, not how productive their engineers are.