Yes, the WW2 Holocaust happened. That doesn't entitle the current Jews living in Israel to "1 free holocaust" coupon.
I took "Never Again" to actually be just that. But in reality it's "Never again to us, and anybody who denounces us is antisemitic!"
Additionally, Israel called dibs first, that is Palestinian/Arabs could have declared themselves a country as soon as the British mandate ended but chose not to. Instead Israel did first and was attacked by neighboring countries which caused the majority of the Palestinian diaspora.
The internationally accepted borders of Israel are based on the 1949 armistice. Israel did not "give" Gaza or the West Bank to Palestine, those are simply the borders. Israel started the 6-day war in 1967 that led to the present occupation.
That's a moral judgement and subjective to each individual.
You said "Israel started the 6-day war in 1967 that led to the present occupation."
Which I said was inaccurate due to the fact that Egypt shutdown the Strait of Tiran to Israel. Egypt started the war.