Radars and bases along the path of travel from Iran to Israel have been progressively degraded. Various interceptor types also have low stockpiles at present. I'm absolutely not an expert keeping well-informed, but my understanding is that Jordan's recent losses mean much of the path is now relatively clear of air defenses, and Israel would have to mount most/all defenses from their own territory for the first time. But Israel is at-present not engaging in the war, preferring to let US do the work, as a minister recently stated. Regardless, it may be attacked, depending on IDF actions in Lebanon.

The Israelis are the only ones that can, and want, to strike back. Besides no one weeps for missiles falling on Israeli cities, so that doesn’t serve the Iranians at all. Lots of much softer targets for Iranian missiles which can’t do anything to Iran.