More I have studied international relations literacy, more surprised I am of how Iran is misrepresented in public.
Iranian leadership is not crazy group of religious lunatics. Ayatollahs are very conservative group of politicians who use religion for political control. There is nothing there that can't be explained by normal power politics. They have goals and constraints. Their main goal internationally is to become regional power with recognized influence. They see themselves as protectors of the Shia Muslims. Destroying Israel is not any of those goals. It's more of a cynical tool to keep connections into into Shia Arabs and Palestinians.
For the Shia living outside Iran (mainly Iraq, Syria, Lebanon, Yemen) Iran is big brother that helps, but is often too controlling for their taste. The West has a tendency to see all Shia groups as mindless Iranian puppets. In reality it's the function of the situation and options they have. Iraqi Shia leaders have established connection with the US and are playing US and Iran for their own goals. Houthis in Yemen are not Iranian puppets. They have their own fight for their own reasons. Iran is just the only one to help them.
Many IR experts see that there is possibility for "the great bargain" with Iran. It would include recognizing Iran's position as big regional power and deal with Israel. It would also diminish the position of Saudi Arabia. The conflict is between Saudi Arabia and Iran over influence is real.