Whoever eventually "cures cancer" will be using one or more AI models heavily in the course of their work. Probably very strong, expensive ones.

That's about all you can say for sure, especially about a topic that is so broad as to be virtually meaningless.

And will also be drinking coffee, and using a computer, text editor, browser, search engine, etc., surely we don't start attributing accomplishments to the tools used?

There have been many incredible breakthroughs in cancer in recent years without it. If the AI money had gone into that, I suspect we'd have better results.

AI seems more likely to help with detecting cancer than curing it imo.