I never asserted that breakers are primarily for shock safety. Next time, please read the post you’re responding to before you misquote me.
As far as grounding, the power company equipment doesn’t care whether it’s putting 10A through a load or an additional 50mA through a human body. The grounding is there so the latter situation is less likely to arise. If a hot wire shorts to the case, breaker will trip vs making the case hot. If breaker doesn’t trip, the case will still be grounded. GFCI makes the latter situation EVEN less likely to arise.
I already explained why sharing a neutral and ground wire is a bad idea.
Face it: you’re wrong this time. No shame in admitting it.
