They are now in a position where whatever Israel does, is responded back by Iran in kind and Israel has no way to defend against it. That's pretty balance deterrence and if that continues, Israel will eventually stop. There is no need to overdo it and escalate beyond a point where Israel regains the upper hand. This balanced tit for tat is enough.
Iran needs to regain airspace, dig out the forward missile bases and sort out the internal sabotages. Those are the mor important things. Once things are in control, they might hit back again. A report by IISS said Iran wants to spend no more than 1,000 Missiles in this conflict and conclude it within this limit, as they want to retain the other estimated 3,000 high-impact, newer missiles, for future scenarios. They don't wanna throw it all on Israel and then sit empty handed if something else comes up.