Limited patriot missiles may not hurt the US too much in a war with China because China will likely overwhelm patriot batteries, and destroy those batteries in one day. Without batteries to fire the missiles, the missiles are useless.
One reason the US does not build that many missiles in a year is because the fuel in missiles degrades and makes the missiles too dangerous to fire, meaning, if we build a whole lot during peacetime, most of the missiles will go in the trash along with the piles of money it cost to purchase them.
Iran has destroyed a lot of important equipment and radars on US bases around the Middle East. These bases are sitting ducks, and the US was unable to defend them.
Iran, being weaker than the US, responds more violently and aggressively to deter the US and Israel, who both may be deterred while taking much less damage.
The Iran conflict, in its low-grade double blockade form, feels like an endless cycle.
Iran has been attacked by a superpower and is technically more able to develop nuclear material than they were a decade ago…they likely want a nuke for defensive purposes more than ever.
The USA is losing its military dominance. It is not adapting fast enough to changing technologies that make killing Americans in war easier. Still, there are many military objectives it could achieve over potential enemies, but the US is not willing to take the casualties necessary to achieve those objectives, and America’s potential enemies know it.