Right, but most US apartment buildings have a room full of washers and dryers for the tenants to use.

They're becoming much more common -- most new apartment buildings since the mid-2010's stack a washer and dryer vertically in a dedicated closet. Less to do with "higher end" and more to do just with designing for it (e.g. washer water hookup, dryer gas and ventilation hookup, and dedicated closet).

In many buildings, the cheaper in-unit machines don't wind up being any more expensive to the landlord than the much more expensive heavy-duty machines in a dedicated area over the long run.

The distinction is, if there is room provided for one, is it expected to be provided by the landlord or the tenant, not whether a typical apartment has one as an amenity.