Iran has an assessed stock of something like 80,000 Shaheds. And you can put them anywhere and everywhere.
Shutting down production of a weapon like Shahed is very difficult because they're simple, cheap, and can be built without a lot of infrastructure.
They can keep building them, dispersed, and keep launching them, from anywhere, and every time they do that they've spent $50,000 at most and the US has spent a million minimum to intercept. That's the economic disparity problem the US is now fighting. It's not about the capabilities of the weapons, it's about the cost of the weapons.
Air superiority is not going to help as much as you think it is, when you're fighting an enemy who is able to attack you with weapons it builds in sheds and garages and forces you to spend a massive amount of money to stop every attack.