one reason is because the ability to profit from patented drugs incentivizes corporations to invest large amounts of money in r&d for novel compounds (sometimes

one reason is because the ability to profit from patented drugs incentivizes corporations to invest large amounts of money in r&d for novel compounds (sometimes a minor variation of an existing old compound) rather than investigating the efficacy of drugs and compounds that already exist and have therapeutic uses since ancient times. This creates a system where life-saving drugs are so expensive that people need insurance to afford them, which shifts the cost to corporations and other people, makes the patient dependent on their employer, and prevents lots of people from even accessing the drugs. Then people react by pursuing "alternative' remedies that may or may not work, and may or may not also have their own side effects, however there is not a corresponding investment in the efficacy and side effects of these "alternative" approaches, allowing quacks and charlatans to exploit the sick, poor, and ignorant.