Zionism is an ideology that took inspiration from the British empire. It was intended to be "something colonial" and pre-dated the atrocities of WW2. The fascist atrocities in WW2 can be interpreted as colonial tactics applied to Europeans, after all the British had been doing extremely bloody concentration camps in Africa and starved India during WW2. For some reason, Africa doesn't get the same play. I wonder why.
So people that engage in colonialism end up doing similar crimes. Israel remains probably the only old school colonial project in the present day with present day technology, backed by the U.S. empire to secure geopolitical interests in the oil-rich region among other things.
Something to think about: America is also a genocidal settler-colonial project and is one of the only nations to back Israel in the UN. Our genocide is still ongoing: visit a native american reservation and witness the immense poverty. Similarly to Gaza, the US state will simply say that despite being an occupying power, these are autonomous zones and we have little responsibility.