All states are illegitimate, however in the realm, or function of The State paradigm, I view The Israel claimant as greater, as it was Israel's historical Homeland, and Jews lived there even through the Disapora.

Now, you can make the squatters argument with Palestine, or might makes right, etc.

But overall The Canananites have the true claim to the land but they kind of got wiped out :/ so I guess then that claim would resort to the second claimant which is Israel.

Even if we make the might makes right argument then Israel has proven that with The Six Day war.

Only argument for Palestine is that they lived there while Jews were still in Disapora but again some Jews also lived there too, so :/