Your are using an argument similar to the repugnant logic of Holocaust deniers. They use claims that Germany could have easily killed Jews /even faster/ as an argument to claim that they didn't commit genocide /at all/.
There's no comparison at all to the ease with which Israel could just drop a couple of bombs on Gaza, had it decided to do so.
Try reading a history book about the holocaust, or even just WW2, and you'll see just how ridiculous you sound.
It was a genocide because they tried to eliminate a specific ethnic group, for no other reason than its ethnicity.
You should go learn more about the subject, if it interests you so much.