Cancer research can appear very stagnant. Pharma companies and researchers funnel money into existing solutions and combinations of existing solutions which increase life expectancy by a few months, and quality of life by a few degrees. Not much foundational research on cures, and why should there be when every new drug which leads to slightly better outcome will be purchased by patients who will do anything to live a bit longer?
Now, how in the hell would VC be expected to improve that landscape? The ideal solution is a cheap therapy which cures cancer. Maybe a cancer vaccine. Where's the money in a 50 (or even 1k) tailored vaccine to cure a cancer when a slightly new combination of cancer drugs can cost $50,000 a month for the rest of the life of a patient?
I'd argue VC don't think long term for the benefit of anyone except themselves. They'll invest in a moonshot if it disrupts an industry for their benefit (e.g puts all taxi drivers out of work) but not if it eliminates an industry (e.g cancer research). There's way more money in funding a slightly different cancer drug.