I think there are markets where competition creates wealth and markets where supply and demand is inherently dysfunctional. I recommend reading about "market failures" where a free market does not leave participants better off. (There are four broad categories of market failures). So the free market works where it does and doesn't in other cases.
Replying to my own comment. If you are wondering why healthcare is specifically a market failure related to
1) Information asymmetry. Patients do not generally know how to select and shop for their treatment without medical expertise.
2) Adverse selection. Unhealthy people want good healthcare, which drives up the risk pool of "good plans". While insurance companies in general want healthier patients, which often leads to insurance firms to compete to offer plans that only appeal to the healthiest people. (I.e who can offer the most restrictive, and cheapest plans) see insurance death spiral. https://en.m.wikipedia.org/wiki/Death_spiral_(insurance)
3) Perverse incentives. Profitable treatment does not always align with best treatment decisions. This both comes from providers and insurers. See information asymmetry.
4) Monopolistic characteristics: A Monopoly is generally defined by a firms ability to restrict output to reach the profit maximizing production (absent of meaningful competition). Try seeing a specialist on an HMO and you can figure the relation to healthcare. Significant regulatory and market capture makes avoiding with health insurance impossible (including your providers insurance), leading to spiraling costs.
Decent description below: https://www.investopedia.com/terms/m/marketfailure.asp