Interesting, my experience has been different, though I haven’t actually checked this in several years (I just always charge electronics first).
It seems like electronics used to ship uncharged because partially charging NiCad batteries harms them, and shipping fully charged batteries is dangerous. Nowadays, Lithium batteries are typically charged at 30% capacity before shipping. Lithium batteries were sometimes sent uncharged for some period of time in between.
I've bought exactly 0 phones with 0% battery EVER, and I got my first phone in -97.