It costs an enormous amount of money to get a drug tested and approved by the FDA. Far more than the initial basic research. The companies pay this money, and they don't get it back if the drug isn't passed by the FDA.

The patent clock starts ticking when the approval process starts, not when it's done. A patent lasts 20 years, but by the time the drug can be legally sold there may be less than half that time left on the clock.

Streamline the approval process and make it less expensive, and it would solve a lot of problems. But looked at another way, you're paying that load of money for a very high level of safety. Is it worth it? Or not?

Once a patent is gone, anybody can make the drug as a generic. The generic companies don't have to do the research or approvals, so their costs are far lower.

You'll get drug companies without marketing departments when you don't have competition any more. That will only happen if the industry is consolidated into a single government-run monopoly.

When nobody has a choice, you don't need marketing any more. Would it be worth it?