> Albert Einstein legally traveled to British Mandate Palestine in 1923
You're claiming that visiting once made him native to Palestine? He was a German. That was his native language, his culture, the world he grew up in.
> Making it sound like all of the land was stolen because some Jews immigrated from Europe is like saying that Muslim migrants are stealing European land.
Have Muslim immigrants to Europe established their own country through the mass expulsion of the pre-existing European population?
The Zionists weren't just immigrants to Palestine. They openly declared that their goal was to turn Palestine into their own country.
> most of Israel’s cities are built on land that was legally purchased
This is simply untrue. The vast majority of what became Israel was conquered, and the local population was expelled. Haifa, Jaffa, Nazareth, Ramle, Lod, Be'er Sheva, Ashdod - these were all Arab cities that Israel conquered.
> the vast majority of Israelis immigrated legally
They arrived under British rule, when the native population of Palestine had virtually no say in its own governance. The native population deeply resented the British promising Palestine to a foreign people, and allowing them to come in and build up their own settlements and quasi-governmental institutions. The Palestinians knew exactly what the intentions of the Zionist movement were, and they obviously opposed it, as any people in their situation would have done. So yes, much of the Zionist immigration was "legal" according to the British, but the British were illegitimate colonial occupiers who were pursuing a policy that was almost universally opposed by the native population.