The difference is that you don't need to run a phase 3 trial to...

The difference is that you don't need to run a phase 3 trial to release a bigger TV or faster mobile phone. That and a whole lot of other government regulations and vested interests.

Healthcare is an industry where scientific and technological advancements take much longer and somewhat perversely tend to push costs up rather than bring them down.

Whilst it is a very interesting idea, I would expect that any anti-cancer nanobots will follow the "healthcare path" instead of the "technology path"... i.e. take a very long time to be something that is approved for use and be hugely expensive if/when they are.