Much of what we consider to be profitable, high-growth business is about taking advantage of market failures. E.g. the advertising industry that bankrolls the internet is basically about taking advantage of cognitive biases to get people to make irrational purchasing decisions. Part of the success of e-commerce is due to the heroic efforts of UPS, etc, in reducing the cost of shipping over the years to make e-tailing cheaper than brick and mortar retailing, but a big part is also arbitraging on state sales tax laws.

This is not a moral judgment (I'm too old to make moral judgments). Fact is that purely competitive markets suck because there is no money in them (there's no high growth startups in the dairy industry, even with extensive government subsidies to offset the effects of vicious competition). A good fraction of the opportunities to make money are based on things like arbitraging regulations or exploiting market failures. Much of the rest involves focusing on markets with little competition (either because it's new or because others don't have the skills to target them), but I think people underestimate how much activity is in the former bucket. E.g. with AirBnB: are they in business because nobody thought to do what they're doing before, or because people thought about it before but realized it was illegal?