But here's a mechanism to mobilize private capital for those diseases that are. Again, the investment needed boogles the mind, around 10B currently, for a single drug.
You're asking someone to pay that money and allowing others to reap the rewards. Why wouldn't everyone want to be the one who didn't pay the money?
Even with the current system everything older than X years is public. That means we should have better care options available then anything X years ago. And that keeps increasing.
Capital continued to exist and there continued to be people who decided what got built and who received them. To me, that's private ownership. I mean, it's not like apple trees suddenly began bearing Ladas. If I wanted to acquire a field to occupy / farm, it was presumably controlled by someone, either an individual person or group of people. I don't see the difference in saying that in one situation my neighbor owns the field as personal real estate, versus whatever terminology the soviets used for why I can't just take it.
Also, the bulk of the cost of manufacturing a drug lives in the scientific & engineering exploration space, which we should incentivize.