Can you clarify? Seems like if a company is making accounting profit, that would ipso facto, in a free market, represent an opportunity for another company to come in, under bid them, and take some of that profit for themselves....and so on until there's none left to take.

There are implicit costs that aren't included when calculating accounting profit. See also https://en.wikipedia.org/wiki/Profit_(economics) and https://en.wikipedia.org/wiki/Implicit_cost