This actually works on OpenBSD, along with ^A, ^E and ^U, in Firefox and Chromium. I suspect it might work on a macOS too, but I haven't tried.
Wow I've been annoyingly using DE to delete a word.
Thanks for this.
FYI, this only works in insert mode, for the word you just typed (equivalent to ctrl-backspace, basically). And diw/diW (delete inner word, delete inner non-space-characters-word) may actually be faster depending on the context since you don't need to get to the beginning of the word.
if it makes you feel better, I often try to close a terminal tabs with ^W from browser habits and delete words ;)
Time to rewire that brain of yours to use 'daw' instead.