Suppose you want your investment portfolio to return 7% a year.
If it has $2,000,000 you have enough cash on cash return to live off. Enough cash on cash return that you might make maintaining your portfolio a full time job.
It's just as much work to get 7% returns on a penny (or $20k) but the cash on cash returns are not enough to make it worth working as a full time job.
Now suppose you $200,000,000. You can buy profitable businesses. You can pay someone else to run them from the cash on cash returns.
With $20,000,000,000 you can pay a team with cash on cash rounding error to figure out how to engineer the system so that small investors usually lose. So that they only win via statistical unlikelihood...aka "dumb luck."
Big money doesn't invest in the same way. Ted Turner had enough money to buy a TV station with the Atlanta Braves thrown in to sweeten the pot. $20k is not that kind of money.