Resistance economy is a good thing given certain qualifiers.
China is an example of such a resistance economy done right because such an economy has to be so airtight and self reliant that if all imports were cut off the next day, the country could still function. Mainly this is because China manufactures everything from electronics to cars to planes. In China's case, they don't even need to import because usually they are the ones exporting to others and it would actually be more expensive for Chinese to import.
Basically Iran has to get to a point where it is cheaper to make some item locally than to import it. The difference between a resistance economy and non-resistance economy is that the former does not have external trade pressures created by internal demand for external products which allows it to "resist."
To some end Iran is already halfway there mainly because it has to be, because of sanctions, importing is not even an option in many cases, so Iran has a disproportionately high ability to manufacture in heavy industries relative to most countries of its size.
You would be amazed how many countries import basic things like steel, chemicals, household appliances, electronics like flashlights, TV's, internet cables. Saudi Arabia infamously even imported sand. Most countries do not invest heavily in manufacturing and that's why they are so weak and helpless.
In Iran, all of this stuff is made locally. Maybe it doesn't sound like much by itself, but when you combine local manufacturing all of these things like steel, chemicals, and internet cables, you have the technology to build a missile. This is why it is so important to invest in small manufacturing, by itself it doesn't look like much, but in the end it adds up, and this small manufacturing of basic things like steel, chemicals, and electronics is why Iran can put satellites in space while other countries can't. You will not find a single independent country in the world that is not strong in manufacturing and heavy industry. All of the strong countries in the world like China, US, Germany, Japan, are all very strong in manufacturing and that is not some coincidence.
What do China, US, Germany, Japan all have in common?
They all makes planes, cars, electronics, and software. In other words, they don't need to import anything.