Now that advertising drugs to the public had ballooned marketing budgets beyond R&D is that still true?

I imagine that dollar-for-dollar a non-profit with the right incentives and oversight could out do the VC-backed leeches driving up prescription med prices.

The vast majority of pure research has funding generated directly from government funds. Medical funding is roughly half from public funds. This wouldn't change with price controls. More profits don't lead to more research.

You're assuming that the profit on the item is enough that it's still worth it if the price is reduced. Why do you make that assumption?

Medicine will never not happen. People will continue to get sick. People will continue to become doctors. We've literally seen this before.

The US subsidizes drug development, that's about all. Other medical R&D doesn't really come out of any publicly funded research system, it comes from medical practitioners. The cost of US drug development subsidy is maybe $40 billion, accounting for basic research and development by pharmaceutical companies. This is pretty much peanuts compared to global healthcare spending. Also, this money is arguably not really that well spent, since most of drug development is useless, and nations can improve their health systems and outcomes much more through things like routine care and monitoring than they will through expensive research.

Can't we keep paying for the R and D and just not let a minority of private actors profit?

The private actors are the ones who pay for the R&D, to the tune of $70 billion/year. That's on the same order as total annual venture capital spending nationwide ($70-$80 billion/year from 2014-2017, though 2018 was an outlier at $130 billion).

These amounts are small enough where the U.S. government could pretty easily cover the expenditures. So by your logic, why do we need Silicon Valley venture capital? Why not just have the government pay for the R&D and make the results freely available to everyone?

Either the government is good at allocating capital for high-tech R&D or its not. Whether you're talking about medical tech or computer tech doesn't make a difference.