[hello_computer]

The problem with immunotherapy--going all the way back to Imhotep--is the same problem with antibiotic resistance: directed evolution. Kill the cancer cells that are susceptible to one treatment (be it chemo, radiation, immune system, or something else), then the cancer cells that are not susceptible survive and continue to multiply. We get a remission, but it comes back later with a vengeance. They know this, so oncology has pivoted to "combination therapy", but many of the official treatments are so toxic that combining them may kill you faster than the cancer.

But you are right about the commercial aspect. More money in treatments than in cures. If a cure ever comes, it is more likely to come from "the people" sharing notes over the internet than Pfizer or Novo Nordisk. But with the amount of money involved, it is an open question as to how long such an internet--where people are allowed to freely discuss things--will survive.