Bad examples of what? It doesn't matter why big corporations keep outcompeting small businesses. They simply do. Thus “planned economies” are still a thing, not something “antiquated”.

It doesn't matter if you think that these are caused by impurities in the system.

Interestingly though, the extent to which big corporations outcompete small business is different in different economies. For example in Europe a much larger part of the economy is driven by small/medium business than in America.