Incorrect. Monopolies do not naturally occur in most markets (with a few exceptions). The barriers to entry that create monopolies arise largely from regulatory capture. Some level of regulation is often necessary, but devising regimes that don't favor early entrants is very difficult. Nobody does this well; neither the US nor Europe.
Often times, companies in the US lobby for regulation that adds barrier to entry. Of course economies of scale greatly contribute to barrier to entry, forcing an entrant to have large volume to even compete. I've read where large companies sell products cheaper than competitors can buy them wholesale. Once there are a few large competitors, mergers happen resulting in monopoly or near monopoly.
Of course industries like food service don't have monopolies, but they don't pay very well. They are also geographically restricted. I don't really care about those companies, they don't contribute much to the middle class.
Google is an effective monopoly, Amazon is certainly headed that way. Facebook is pretty close. Microsoft would be except the rare occurrence of someone writing a free operating system that was very good at the dawn of the internet age. Airlines are effective monopolies in their selective hubs. Monsanto certainly. They don't have to be the last company standing to show monopolistic tendencies in my mind. Microsoft wasn't technically a monopoly in the 90s, but it might as well have been.
