Because Iran is a paper tiger and are completely unable to mount any kind of response. They have sent ~100 UAVs and almost all of them have been shot down (though that is according to the IDF) Otherwise Iran has been silent on action, but loud on words. Just like they were before the attack.
Here is what Iran has done so far ~18 hours after the attack.
Meanwhile Israel is still continuing to run roughshod all over Iranian Airspace with impunity and attacking targets. Mossad is operating on the ground and very well may be planning to assassinate more senior officials.
This is what Iran said before the attacks:
https://www.aljazeera.com/news/2025/6/12/iran-doubles-down-as-us-signals-israel-could-strike-during-nuclear-talks Note that most of the spokesmen for the Iranian response in that article are confirmed dead by the Iranian government as well as the IDF.