Diminishing returns for Israel now
Iran adapted and lost far fewer missile launchers the second time, and they are easier to replace
Most of the missile inventory is safe in the missile bases, the U.S. and Israel fired huge amounts of massive bombs on these bases every day and only managed to temporarily block the entrances
Production is slowly moving underground (difficult to move fully underground), and it seems Iran is not making serious efforts to restore overground production right now anyway. Perhaps because stockpiled components are sufficient to restore inventory for now