Buying the land legally from other occupiers, the Brits. The native population was never asked if they wanted to receive an influx of refugees from Europe, refugees that other European countries and the US straight up refused to take in.

Besides that, many Palestinians were indeed ethnically cleansed, and this is not even a debated fact, former Israeli soldiers came clean about it in interviews, talking in great detail about all the war crimes they committed.

The 20% Arabs in Israel you are talking about, although Israeli citizens, still do not enjoy the same rights as the jewish population.

I know all of this, I’ve been to Israel, I have jewish ancestry and relatives there.