I'd love a dumbwaiter simply for a place to queue items "this needs to get put away downstairs (next time I am downstairs)" etc. Instead I just use the shelf next to the stairs. Which doesn't work if I'm already carrying something to bring up/down stairs, and that pattern makes it so I'm likely to forget even when my hands are free.

I built a cart/track system that went from the basement to the outside via the bulkhead. It fulfilled that work pattern in some regards, but it also made it hard to use those stairs manually [0] so it also impeded getting things done. The design that kept the cart level used up way too much of the vertical space. The next version of this idea will be aimed chiefly at heavy things (with the commensurate work to tie down etc), and go through two transitions horizontal-sloped-horizontal,

[0] and yes blocking an exit is fire hazard I know I know