I can’t remember the last time i fell off on my commute to work.

The only time I've hit my head while biking was on my way home from running an errand (so not exactly commuting, but still utility cycling). I was riding past a construction site and, being an engineer, was distracted looking at the structure when my wheels caught the edge of a metal plate covering a hole in the road. I keep my broken helmet as a sort of memento mori, because it definitely would've been bad if I hadn't been wearing one.

On an individual basis, IMO it's always safer to wear a helmet than not. On a societal basis, helmets for biking should not be required because it's better to have more people biking than to choose to drive instead.