Why do capitalist extremists (e.g. ancaps, ultra-libertarians, minarchists) tend to ignore the flaws of free market systems?

So I'd say to most people, even to most capitalists it's clear that free market systems are not perfect and have certain flaws.

In economic literature there quite a number of market failures that are widely recognized, such as:

- Externalities

- Monopolies and market power

- Information Asymmetry

- Missing Markets

- Coordination Failures

- Short-Termism

And so I find most capitalist extremists act like those kind of market failures simply don't exist and wouldn't cause any problems in a hypothetical unregulated laissez-faire market economy. And while I'm not saying that all regulation is necessarily always good, the fact is of course that many forms of regulations and interventionism got implemented exactly because we realized that markets often fail if left unchecked.

Like in the US for example there were some massive monopolies in the 19th century. Wide-spread market collusion, formation of cartels and monopolistic practices was pretty common in the US in the 19th century. So that's why eventually in the late 19th century the first anti-trust laws and anti-monopoly laws were implemented, because people realized that without regulations and without laws corporations will often collude with one another and form cartels in an attempt to manipulate the market.

Or like after the Wall Street Crash of 1929 that led to the Great Depression eventually in 1933 the first Securities Act was passed. This was done because it was recognized that " Information Asymmetry" could lead to serious market failures that could have catastrophic effects. Without any regulation in place many corporations may provide the public with inaccurate, misleading or just outright false information about their financial health and their business operations.

Food safety laws were passed for similar reasons. Consumers will often lack comprehensive information about the ingredients and safety of the food they buy. Without regulations consumers will often be at a disadvantage because there's so much information that just isn't openly available, like the way companies handle food products, the ingredients they use, measures they take to prevent food-born illness etc. etc. And so food safety laws were actually passed because major problems in the food industry had been exposed that often led to illness or even death amongst the population.

And so those are just some examples of common market failures and regulations that have been implemented to address those market failures. But very clearly free markets are not perfect. There are some major problems that exist if markets are left unchecked. Free markets have some major weaknesses.

So why then do capitalist extremists often act like those problems do not exist? Why are unregulated markets a good thing, when it's clear that those markets have some major flaws and weaknesses?