The relative drop in oil prices is, exactly, the reason. In general, oil companies’ profits are spiking up because the ground is running out of oil, so instead of reinvesting in refineries and extraction equipment, they’re able to just keep all the money. I heard it referred to as “the party at the end of the world” - basically that’s why their profits are sky-high compared with what they’ve been historically. On top of that, last year, they had the luxury of super-spiking oil prices as well, but the oil prices have gone back down, so their profits have shrunk back to being merely conventionally obscene.