Of course there is no such thing as "stale air" like a stale cracker. Rooms that have not been properly aired become musty-smelling from the excretions of organisms, both micro and macroscopic. In recent years, they also amass plastic and glue byproducts that evaporate from synthetic materials.
I suppose that air from cans may lack the "freshness" of outdoor air, but much of that is the smell of ozone.