Great question. we have a first floor laundry and the room lands right above the one bedroom closet so I had plans on building one at one time. She said she didn’t want it unless I made it a dumbwaiter and that sounded like too much work.
I went to army surplus and bought the really nice GI laundry bags for 3 bucks each and they get the job done for now.
The only new ones I have seen lately have a door like Neal mentioned that is spring loaded with a string you pull from below to open it. not sure if that’s because of code or not.