Funding is the essence of scarcity. Funding one thing means those money will not be funding anything else. But you're free to be content with countless minor variations on existing treatments [0]. Curing cancers will require an actual breakthrough.
Total funding for all human activities is scarce, but can go to anything. Money spent on video games could instead be used to fund cancer research.
Thus the percentage of that funding going to medicine isn’t fixed. We essentially spend extra money on this kind of research rather than diverting cancer funding to look for new pain medications. Further, people with sage IV cancer really have benefitted from better pain meds it’s not as useful as a cure but it’s still useful.
Capitalism has freed 90% of humanity to do something other than farm food. We’re in the 3rd stage of human history first almost everyone was hunter gatherer, then nearly everyone was farmers, now people do all kinds of things. How we spend that seemingly boundless surplus of labor may not seem efficient, but it doesn’t need to be to be dramatically better.
Progress is exponential. So looking in the past and saying we should be content with a 90% improvement is misleading, because it is dwarfed by how much more potential there is.
That exponential is based on the increase in number of people not farming. Graph the number of writers/scientists/engineers/etc over time and it’s an exponential, but population isn’t expanded exponentially any more.
[0] https://duckduckgo.com/?q=capitalism+breeds+innovation&t=fts...