For FSD to be a net benefit, it only has to be better than an average driver. It's quite possible that FSD will be rather used by below average drivers (with excellent drivers opting to still drive themselves), further increasing the benefit.
We are a LONG ways off from FSD being better than the average driver. Anyone saying otherwise is apparently living in the Bay Area or one of the places an influencer lives that Tesla tries to game the system, because it is trash everywhere else. It still can't handle navigating a road that has the option to continue straight or go around a curve which even a novice driver can navigate without pause.
How to I objectively test if I'm a good enough driver to be better off without FSD?
This could be due to Dunning-Kruger, age based trust of new things, socioeconomics, etc.
if the best driver in the world dies because they used FSD, then fsd is the cause so it must be as good as the best driver in the world to have not killed that human. q.e.d.