Humans are simply incapable of paying attention to a task for long periods if it doesn't involve some kind of interactive feedback. You can't ask someone to watch paint dry while simultaneously expect them to have < 0.5sec reaction time to a sudden impulse three hours into the drying process.
FSD doesn’t lull humans into a false sense of security, humans do. FSD doesn’t let you use your phone while it’s on. This alone is an upgrade over most human beings, who think occasional quick phone usage while driving is fine (at least for themselves).
I believe that if you replaced all human drivers in the US with FSD as it exists today, fatalities would go down immediately.
Humans are not a gold standard, and the current median human driver is easy to outperform on safety.
I’m sure things are very different out around the edges, as you note, but the majority of the time humans in cars kill people it isn’t because they were in an edge case - quite the opposite. They were just driving home from the bar like they do every night.