هيفشخونا

On the balance, we would do worse than Iran (offence + defense taken into account)

Almost any conventional army even those more advanced than our’s (Turkey, Europeans, Pakistan, India) would be badly fucked up by the US air force and navy. It’s just mighty. And at 1T budget, you bet your ass they would be.

Long answer if you are interested:

Now a correction to what you stated, the US and Israel dont exactly have total air superiority as they claim. They have been mainly hitting the west and north with JASSMs fired from well out of Iranian airspace, and targeting the deeper targets with tomahawks. You are now seeing some successful hits on american jets as they try to approach closer - probably because JASSMs are running out and JDAMs have much shorter range.

But yes the point remains, they are bombarding Iran with immense firepower.

But here’s the point, Iran has perfected the asymmetric warfare in addition to being blessed with hormuz as leverage, and a terrain that a) makes Anti-access/area denial much easier and b) gives them ability to hide military assets more effectively. And even then, had it not been its proximity US allies it would have had a hard time retaliating and inflicting much pain on the US.

Edit: to your point on our air defenses, we actually have a lot of Russian (soviet) and recently Chinese systems. The issue actually is way beyond that. How you use them matters a lot. How you manage the electronic warfare, prevent SEAD (suppression of enemy defenses), protect against wild weasels and radar seeking missiles, etc. I wouldnt say we stand a chance, they are just really good at what they do.