The Iranian's regime's minimal goal is regime security. To that end, it aims to apply maximum pressure/cost on Israel/US, and hope that they will relent at some point. Iran has no other means to actually cause the Israel/US to stop (as in, it lacks the ability militarily deter or defeat).

Iran recognizes that it is not just the actual damage, but the credible threat of damage that incurs pressure/cost. For example, there are piles of ships holed up in the Gulf - Iran has the capability to strike at them, but they don't need to. Publicity is part of magnifying the threat.

Iran likely lacks the capability to actually assuredly destroy any single target of its choosing. Iran instead likely has the capability of destroying maybe 1-10% of targets that it actually chooses to engage. However, it can hold hundreds of targets at threat to try to ratchet up the pressure. In addition, by casting an ever wider net of claimed targets, when it does get around to attacking, it's more likely to be able to construct a narrative of "calling their shot".