Economics/wealth is not a zero-sum game. If it were the economy would only have regressed since the stone age (bigger population, same amount of wealth: less wealth per person)
So the sum of wealth increases due to workers adding value to or with the fruits of each others’ labour. Wealth does not start out at a maximum from which one can only extract.
People produce things, that other people buy and produce even more with. Long ago, a few guys working in a garage bought a few computers, and wrote software for them; now Microsoft is one of the biggest companies in the world, having its own very impressive offices. IBM (the company they bought their computers from and developed software for) is still a big company. In terms of Operating Systems for PCs, not so much, but that’s a different matter, they both profited from the succes of MS-DOS. So, leaving aside market saturation, which is different (and to a certain degree, that is a near zero-sum game), but their mutual succes helped the both of them.
Why is there so little political freedom? Because freedom IS a zero-sum game: the more freedom the people have, the less power the regimes have. And vice versa.