The oil does in fact stop lubricating well too. Shear is a thing and the additive packages stop doing their magic over time too.
Still, unless you live in the desert, the body of most cars will rust through long before you spin a bearing and those are the parts that are most affected by lubrication. Unless you completely neglect oil changes of course. I'm on only 420k km and already the 20 year old rocker panels are perforated on my Audi. Engine probably has another 200-300k km in it, but the car will be unsafe to drive long before that.