Small nitpick here. For drugs, novel drugs in particular, 20 years is actually the required amount of time for the pharma companies to actually turn a profit. The patent applications are submitted as soon as a viable drug is discovered. After this, it requires 10-15 years of animal testing, clinical trials, etc with costs amounting to 100s of millions to billions of dollars before it can be brought to market.
https://www.healthaffairs.org/doi/abs/10.1377/hlthaff.25.2.4...