There are two core insights here that are actually pretty obvious:
1. 20% of 1200 is more than 20% of 800. Duh! But the practical insight is simply that people with more wealth can afford bigger bets and expect bigger payouts.
2. Many systems are sensitive to initial conditions. In this model, the first coin flip matter vastly more than all others and determines almost the entire outcome.
As others have pointed out this is really not a good description of the economy as a whole due to its zero-sum assumption.
However I think it’s a relatively useful analogy for the stock market and how other passive investment markets work.
Passive investment is a larger percentage of the economy than ever before and is increasingly how the “rich get richer.”
A very simple distribution solution therefore is to stop privileging capital gains and tax all income equally. But of course this has been considered and hasn’t gained traction.
Another solution is to disrupt passive investment markets. The one that comes to mind is rental housing. If we made it much much easier to build housing then then rental housing market would be like the used car market: viable but not an easy place to sit back and make passive income.