It's not so cut and dry. One reason Aramco is worth so much is that the cost to extract their remaining reserves (on a per barrel basis) are one third of costs

It's not so cut and dry. One reason Aramco is worth so much is that the cost to extract their remaining reserves (on a per barrel basis) are one third of costs in the U.S. A collapse of oil prices may decimate the energy industry in the developed world (which extracts from offshore or unconventional sources) and would mean Aramco becomes the only supplier. Now obviously they wouldn't be able to raise prices beyond a certain level, but they have many decades of guaranteed cash flow remaining.