Well, if the dumbwaiter idea is feasible, you'd just put the dirty laundry in the dumbwaiter, tell the dumbwaiter that it's dirty laundry (maybe provide further classification like "this is a white towel" or "this is a pair of blue jeans"), and wait for notifications from the dumbwaiter system to know when you can ask the dumbwaiter for your laundry back. Wondering if you could even build some kind of camera and some kind of clear washer and dryer that could track individual pieces of laundry such that the laundry of multiple tenants could be washed together to reduce wait times.

Considering the trend for new construction is to have luxury housing, while problematic in general for much-needed affordable housing, maybe it represents an opportunity to develop a system like this, whereby a developer installs the dumbwaiter in the walls, sets up a dumbwaiter floor, and is the primary investor in a startup that builds out the dumbwaiter tech. As the developer builds out more buildings, and the dumbwaiter can do more things, buyers will pay more for units with the dumbwaiter, and the developer can possibly even license out the dumbwaiter tech to other developers.