Lemmy won't catch on until there are groups of communities you can ban at once. Sports, Linux, German, pervy anime... It's a very rare user who will put up with the absolute dreck of the initial feed and manually block communities until they have a feed that's marginally personalized.
Then there's the fact that any communities that are specific to peoples interests are completely empty.
Probably one complication is that the trucks need to be able to drive while the bed is up in normal operation. They have to move forward while dumping to spread the load.