Bearings and shocks have grease, sure. But those things last decades after installation. They're probably two orders of magnitude lower in volume consumption than engine oil, which gets contaminated and disposed of at the rate of like a gallon or two per vehicle per month.

Like, the price differential is so high that the high end artisinal lubricant market is dominated by chemically synthesized products that aren't strictly petroleum at all (though many of the reagents used to manufacture them probably come out of the petrochemical world).