Human living in the modern age involves some waste. Reasonably clean people try to keep theirs contained to avoid interference with their life. There are many wastebaskets that must periodically be emptied into larger sources. At least once per week, most homes have a garbage pickup day, where a company takes the garbage from one place to a landfill.
On the garbage pickup day, all the trash must be centralized at the pickup point. If all containers are the same, then this can be done robotically, saving 15 minutes of work per person.
15 minutes that I hope they use to improve the world.
As for the landfill, it would probably be a good idea to have a hobo rifle through it for useful things (such as metal) sometime.