Iran has 90m people. That's more than double of Iraq and more than triple of Syria. Libya only has 8m.

Israel wants Iran to collapse. They don't care if what comes next is stable or not. Millions of people who don't want to get caught up in the terror of a failed state will leave and flood the neighboring regions.

They won't be accepted in other middle eastern countries and will likely end up in Europe. Since Europeans are the only people stupid enough to accept millions of refugees.