The Saudis tried petro-power politics by driving prices up through cutting production, but other OPEC members immediately increased production for the additional lucrative revenue.
OPEC has been dead for a while -- why? It was a cartel that survived on the basis of raising and lowering production in unison, and now it is a race to the bottom. The Saudis were betrayed and this is their revenge.
The oil flood is as much about punishing other OPEC members as it is about killing potential Iranian oil revenue.
Or, the Saudis realized that they make more money in the long term with price swings than a steady increase.
At 100$/barrel people would just switch to something else. At 100-40-120-60-200, people are going to keep buying low mileage gas powered cars in massive numbers, building car infrastructure, and living in the suburbs.
PS: Don't forget you can manufacture oil for
~100$ per barrel, but if your factory folds when prices drop under 90$ it's a poor bet at those prices. It takes huge investments to create an alternative over decades, but you can kill them off with a few lean years.
The $100 dollar barrel was a huge mistake, if the price was engineered through cartel maneuvers. It launched shale oil but, much more importantly, it made solar cheaper one decade ahead of time.
The solar energy cat is out of the bag[1], it will forever loom over oil.
OPEC seems to be dead - and that means we're getting real competition in the oil business.