https://pmc.ncbi.nlm.nih.gov/articles/PMC11107028/ basically kickbacks screw over patients by raising end costs.
Pharmaceutical companies engage in behaviors known as product hopping, e.g. making variations to prevent revenue loss when the original drug goes generic: https://jamanetwork.com/journals/jama/article-abstract/2831386
In addition to the lobbying and wine and dine doctors get the other poster mentioned, the US is one of only two countries that allow marketing of prescription drugs to the consumer (e.g. tv ads). Insurance is also notoriously horrible. Because of how scammy everything is in the US medical system, it's no wonder that people have stopped trusting it in the form of antivaxers, homeopathy and other quackery, etc.