A couple thousand Hamas terrorists with improvised rockets, rocks, and whatever little they manage to smuggle across some of the most tightly controlled borders in the world are NOT an existential threat to the country that controls those borders and have one of the most powerful and advanced militaries in the history of humanity, with millions of actual and potential recruits.
They’re fighting NOT to protect their own existence, but to kill or displace all Palestinians. The vast majority of whom are innocent civilians, of course.