so basically, you don't care about moral fairness and are fine letting monopolies rule markets and societies. The extreme side of "equal opportunity".
I won't make a moral argument here, but merely a logistical one: country governments have a lot of incentive to not let this happen. For the sake of technological progress, for the sake of ensuring the non-upper class economy (aka, taxable income that won't play Matrix with them in terms of evasion) is healthy enough, and for the sake of minimizing risks of a hostile takeover (be it from the monopoly or foreign powers).
So a truly "free market" only works in a vacuum with benevolant dictators and a united world government. That may take a while.
>The "average person" does not exist
hence why we have multiple fields dedicated to approximating such a person. Because averages are still valuable for many things. From government policy, to targeted marketing, to identifying societal biases.
Fairness at its most objective is merely a process. It's not and should not be proselytized as a guarantee of equal outcomes irrespective of circumstances.
> Or is there possibly a level of “fairness” that’s evident to the average person?
The "average person" does not exist and thus doesn't have an opinion representative of an arbitrary individual or group of individuals. A rational flesh-and-blood person can only speak for himself.