The pipelines are full. The tanks are full. The ground is full. Buying a bunch of oil and sticking it in Louisiana salt mines is not helpful. First its not that much. It wont last us very long. Second, we can always fill it if we think we may need it in the future. Third, one bomb and its gone. Same with Cushing. Fourth, you still have to refine it. We have lots of pipelines crisscrossing the country that bring oil from fields to refineries quickly and cleanly. The Strategic reserves is like us pumping oil out of the ground and then pumping it back in so we could pump it out whenever we wish.
Yes, it was a great idea in the 60’s but now, with fracking everywhere. Its just not needed. The situation may change in the future. But for now we have huge reserves in the ground that can easily be piped to our refineries. We leave most of it their because oil is cheap. But if there was a crises we could add a million gallons in a month.