You really think they don’t know where Hamas’ leaders are? They know, but it’s probably impossible to kill them, since they hide under hospitals in underground tunnels, and no type of ammunition can penetrate 30m deep underground without obliterating the building above it. No country in the world has faced these kinds of fighting conditions, and even the U.S had trouble fighting in the middle east because of probably these same reasons.
They’re not fighting another army, with a base and well defined targets. They’re fighting a terror organization operating from civilian homes.