No they're exactly right: drones need cheap, powerful parts which have only become possible due to highly concentrated mass production in places like China. You aren't fabbing up integrated machine learning SOCs in a shed in Ukraine, and the cheapness of the parts depends on large unfettered supply chains. They're not "with some skill, you can build a lathe and then machine a pipe gun" simple.

In a direct conflict, no one is going to sit back and be destroyed by drone swarms: they'll bomb the industrial districts.

In war, the enemy gets a say in your plans: Iran can't beat the US directly, but it can hit energy infrastructure around the Gulf which is politically untenable for the US.

But it works the other way too: if your enemies plan is "you won't bomb the big industrial facilities so we'll just win" then you break out the fancy expensive missiles and bomb the industrial facilities. Or the power plants.