The argument makes sebse for some things but not for others.

Take water bottles. Or mugs. Having 15 of them collecting dust in a drawer is suboptimal. Therefore no one should own one and rent it from a muglord.

There's a balance to be found, and I'd say RAM is more of a commodity than cars are. The fact it's not 99.999% utilized, unlike a certain someone's wishes is a feature of life and not a bug of capitalism not yet being post late stage.