alt Hacker NewsIf Iran was having great success with their attacks, they wouldn't therefore tail off the intensity if they could help it. They would just start scoring more hits with the same, presumably maximum, rate of fire.
I think the obvious answer is the correct one here, that Iran's launch capacity has been degraded. That's not to say it will ever go to zero, so a lot of your other points still have some merit.
That assumes they want to escalate. So far at least their official statements have been clear about tit-for-tat.
It could also backfire spectacularly. If a bunch of civilians suddenly get killed or other war crimes committed unilaterally by them (such as targeting energy infrastructure) their adversaries could gain political support for the current effort. Whereas gradually forcing all interceptors to be expended is a massively expensive slow bleed and gives the opponent little to nothing to spin in their favor.