Saudi Arabia and Israel are united in their opposition against any reconciliation with Iran. For very similar reasons.
Israel doesn't want strong adversaries in the Middle East. So it always tries to crush the strongest country available. That used to be Iraq and now that that is finished it has turned on Iran. Don't expect Israel to rest when Iran has become just as wrecked as Iraq: it will just start looking for the next strongest country in the region and target that. The alternative is reconciling with the Arabs. But that would mean giving up on stealing Arab land and that isn't popular in Israel. It doesn't help neither that Netanjahu is the kind of politician who thrives on sowing hatred.
Saudi Arabia is a country that was only formed in 1932. Its cohesion is weak. In fact it is just the project of the rapacious Saud family. It is somewhat doubtful whether the country would have survived without oil. Yet nowadays the Saudi has big visions of Saudi Arabia as the most powerful country in the Middle East. As he lacks the forces to project such power himself he depends on his money to seduce other countries to do the dirty work for him. As Iran is the strongest country at the moment it is the natural target.
So we have two countries that are inherently weak yet want to be kings of the hill. Both want crush the strongest country available as a threat to this ambition. But as they themselves are too weak to dominate that just will open the door for another country - that will become the next target of their ire. This is a whack-a-mole game that will never end. Western countries who let themselves be seduced to participate in this game will sooner or later conclude that they are fighting for a bad cause.