one could argue that in the long term book buying consumers are protected from a monopoly that would probably appear

I find this argument overly theoretical and unsupported. Book selling isn't a natural monopoly. If Amazon dumped books and forced out everyone, can they really then use that monopoly status to raise prices? The market has a fairly low barrier to entry and any attempt to have high margin pricing would be met with new competition pretty quickly.

> can they really then use that monopoly status to raise prices?

No, they can use this monopoly status to extract data or otherwise bully consumers (which they do). Private monopolies are inherently bad.

Yeah I agree with that. I just don't think they can dump books effectively.

Does that monopoly result in increased cost for the customer? I assume there is harm to the general economy the problem is quantifying that and also convincing people to pay more for something.

Monopoly may not result in increased prices, but it does result in increased risks. Which are essentially “hidden” costs for customers.

But they do so by creating a new monopoly where there publishers set the price.

That’s not what a monopoly is.

Yeah. More people writing books, writers making more money, therefore producing more content, people ending up being able to read better, more books as a result - pretty bad for the consumer.