Both their functionings are complex, so people can get impressed. But for both of them, all the complexity is inside the device and there isn’t much to put together; and the way they hook up to your house is really simple.
Why YSK: so you don’t live too long with a broken toilet or garbage disposal, thinking it will be too hard to replace. Those two are some of the simplest things to DIY.
They’re pretty great for reducing the volume of your waste for those of us who care about such things. Supposedly they can also help increase the longevity of your pipes by reducing gunk buildup. And when I lived in a tiny apartment, it was pretty nice for getting rid of smellier foods instead of letting them sit in the trashcan or having to haul it out to the dumpster.
I lived a long time without one and wouldn’t say they’re a necessity or a big game changer or anything. But it’s a pretty nice convenience.