When I was growing up, these seemed to be ubiquitous and I never liked them. They seemed overcomplicated for the purpose, and created a gross and smelly area under the sink that needed more cleaning.
I haven’t had one in years, as a simple sink mesh does the same job. But I don’t really know how other people are. Are under sink garbage disposals still common, and commonly actually used by people here?
Currently live in a condo, I think every unit in the building came with one
The biggest advantage I could find is that they are insanely convenient for making French press coffee! French presses are otherwise a pain to clean (since there’s no filter to aggegate the grounds), but having an in-sink disposal means I can just flush the coffee grounds directly into the sink. Besides this though I’m pretty indifferent to them