"One drug might only work in 10% of people while another cure might cure another 10%, and so on."... I believe this, to some degree. But I don't think it's that much. A lot of drugs get killed because of side effects, poor bioavailibility, unexpected responses, interference with other drugs that are common or necessary in the cohort of cancer patients, etc. Those things are much harder to predict. It is embarassingly easy to find compounds that kill cancer cells in vitro.

However, this:

"Cancer results from finite genomic mutations that biotechnology can easily list."

Well the first part is true. The second part, not so much.