The oil reserves are not serving the purpose of controlling oil prices. You would need a truly astronomical amount of reserves to control the market, which isn’t exactly the best way to use your nations wealth. Buying more during the dip would not have changed the current situation.

Which is why, the only feasible solution to controlling oil prices is to change it demand side. Oil does have legitimate uses for eg military, petrochemicals etc. but most of it is just burned away.

Layman here. As I recall that dip was actually negative prices because no on could take delivery. Was there actual spare capacity to store more oil at that time?

Yes, in the strategic oil reserve there was, but not in many other oil storage facilities, and government buying processes for everything are slow and complicated. However, the negative prices aren't for oil as delivered where you want it. It is for oil coming out of a tap at a storage facility somewhere in Illinois (or rather, entering a tank that you rent in that storage facility). All of those tanks were full when oil prices went negative, and there wasn't enough demand to transport oil out of that facility. Most storage facilities were full, and new ones couldn't be built in time.

Buying the dip would be a cost effective way of maintaining our insurance policy. Buy low, sell high. We had saved cheap oil for a hurricane and released them for a light drizzle in order to try to cap gas price increases, which have more than doubled from one president to the next.

I don't understand - we sold high (>100) and can now buy cheap (~80). What you want is what's happening. What are you screeching about?