#1) Psychedelics/psilocybin for mental health. Cost basically $0 to produce but the US Mental Health industry was a $225B industry in 2019. Now though big pharma sees the writing on the wall, so is inventing patented variations (https://www.npr.org/sections/health-shots/2020/12/09/9445723...) because otherwise these natural substances that people have been taking for thousands of years wouldn't be "safe".
#2) Oxycontin. We have far better cures for short-term pain management. A 1996 internal email from Sackler: "get an audience for our patent infringement suits so that we are feared as a tiger with claws, teeth and balls, and build some excitement with prescribers that OxyContin Tablets is [sic] the way to go.15" (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5234149/)
#3) Unnecessary procedures (440k/deaths year from medical errors -https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5234149/)
1) Psilocybin research was, and it probably still is in most of the world, made ILLEGAL by governments. Another causality of the war on drugs, who wrongly imprisoned thousands and caused countless victims so that a few politicians get re-elected.
2) > We have far better cures
So you’re saying there are cures. Great then. Please re-read the gp's question. For 3) as well...
Name three, and give reasons to believe that there's no cure for business reasons. If you can't name at least three (of the "many conditions"), then how can you be so sure of this?