from the sale of products they've invested years of research in. From angel funding and capital from the market, wealthy backers and philanthropists.

I find it hard to imagine that you could keep asking for more and more funding on a promise for a cure for something in 5-10 years down the road, and continue to have the same private individuals with very little personal wealth continue to throw their earnings at it.

I imagine that individual smaller projects may well benefit from it, but crowd-sourcing cancer or something equally grand, people would lose interest in it. Not because they don't care, but because human beings have human timescales attached to expectations. Something that has a hard to quantify immediate success or reward attached to it is less likely to attract attention and investment.