Whatever their ancestry, they came to the land as invaders from the Aegian. Hardly a good claim to the land. And the Palestinians are Arabs anyway, not descendants of Philistines.
The modern-day “Palestinians” are certainly Arabs. Their name is a pretense, and so admitted by Zuheir Mohsen back in 1977.
I certainly agree as to the invalid claims to Israel by the original Philistines, never mind today’s “Palestinians”.