[TheOtherHobbes]

Aggregation theory is nonsense. Not all costs are technological, and similarly not all customer costs are direct. While aggregators exist, you can't understand the market-distorting effects of monopoly without appreciating the entire picture of capital flows within the system from surrounding businesses to the monopolist.

The second order effects are at the heart of antitrust action. Monopolists distort markets in ways that force everyone to pay extra even if they do not pay the monopolist directly.

For a trivial example, consider that dealing with SEO is a huge and expensive problem for any startup. If you don't appear in listings - preferably by buying ad spend - you may as well not exist.

Someone has to pay for that, and those costs will be passed on to customers in most Internet transactions. How much they pay is strongly influenced by Google's choices.

If search wasn't a monopoly those costs would be lower because there would be competition.

This is far from the only example of a market-distorting effect that generates extra costs for businesses and customers because of an online monopoly.