There have been a couple DYI solder paste dispensers, both for the Original and the 2.0 .
I don’t think anybody has attempted the part picker and placer though. As @buckfast_beekeeper mentions, there are a ton of variables to work out, and you’d have to somehow mount them to the bed where the toolhead could reach them. Orientation, packaging, advancement, etc.
If you have a PCB with paste dispensed, placement is a lot easier, since the solder paste will help anchor the part to the pad.