After the creation of Israel the Arab world expelled (directly or indirectly) all Jews (Arab Jews) of which 2/3 of all modern-day Israelis are or descend from partially. Economic blockades have been ongoing for decades (since the beginning). Wars were also fought.
However it is a war that not even a united Arab world let alone a united Muslim world can win due to Israel's close ties with the US (basically a illegitimate child), the West (Europe, Holocaust guilt etc.) and even Russia which has close ties to Israel due to a large Russian Jewish population that is influential within Russia as well (politics, economics, military).
Arab governments don't speak for the Arab people. That is the problem. Hence the lack of unity on many fronts. Practically speaking it is also difficult to get 20 + countries and 500 million people on board on the same strategic projects and political ones.
It is well-known that those who are the closest (brothers, cousins, family members etc.) can tend (or tend to have) the biggest feuds and disagreements.
That news of a Indian airliner crossing Saudi Arabian airspace was/is fake news. Similar to the absurd news of Israel selling the Iron Dome (LOL)
to KSA when operates the Patriots (that have proven themselves to be 95% successful in the Yemeni conflict), has agreed to buy THAAD and the S-400 as well while working with Ukraine on this front as well.
Palestinians cannot even count on the PA (Abbas). Or the world. The same superpowers that preach democracy, go to war to install it far away in foreign lands are silent despite 70 years of oppression from Israel and numerous incidents of breaking international law.
Israel is untouchable as things stand right now. Nuclear armed. They have the US in their pockets foreign policy wise too.
Even hypothetically speaking, if all Arabs ganged up and invaded Israel (all together, in a coordinated fashion, without any internal disagreements, treason, intrigues as in the past) Israel would be invaded easily but what do you think their response would be? They would be forced to use nuclear/hydrogen bombs and have in mind that Palestinians and Israelis (some 15 million people in total) live in a very small geographic/confined space. So it's almost impossible not to kill/attack a lot of Palestinians if you decide to attack Israel.
Brother
@Falcon29 might expand more here.