Garbage men are working one of society's most important jobs. They're deserving of respect for the hard work they do. If UBI results in underpaid people leaving, employers will have to raise wages to match the true value of the job or they'll invest in automation. Either way would be good.
Pretty hard, have to solve self driving trucks first, there's already just 1 person on a truck operating the remote arm in places where roadside bins work (ie basically anywhere other than the urban core).
Ever seen all the kinds of things people put out for the trash, and how dumpsters can be overflowing in various different lots? It won't be easy to automate.