Major price collapses lead to a rationalization of assets. This occurred after 1985. High cost production was shut-in, development plants were shelved, cash flow was reduced, rig counts went down, companies were restructured, downsizing occurred, assets got sold and companies merged. But even this is not the end of the story. Companies may exit the business.
Companies restructure in order to survive.
Complacency is not an option. Low prices set new, more-demanding investment criteria. So successful companies learn to survive in a lower price environment. And the successful companies are likely to expand market share at the expense of higher cost producers. OPEC gets squeezed.