That's not the problem. It's when the little guys try to compete with what the big giants are doing and get completely blocked out. Amazon/Google are all about being magnanimous and supporting startup growth, just as long as they are getting a piece of the action and that it doesn't threaten their market duopoly too much.
Not every market and product needs to be accessible to the little guy. Things like infrastructure have huge scale benefits, and if the big guys are doing it at modest profits already and some at a loss it's very economically efficient.