Exactly. I passed a rubbish man on the way to work this morning. 1 Man, 1 robot arm. The arm was manual, but it was set up so that the driver could do it himself. Drive up, pull the bin to the arm, arm dumps bin into dumpster, rubbish man puts bin back where he got it, climbs back into vehicle and drives forward to the next bin. Admittedly this was on a "rural" road where no one was parking on the street.
We don't really worry about weight, just volume. Put all you want into the bin, but make sure it slides out okay. If it doesn't, that's you problem, you get to pay for the pickup even though it wasn't picked up. (hint: you shouldn't fill up your bin with mud that will stick to the bin). There is a practical limit though, if the rubbish man can't move the container to the vehicle (in the case of the aforementioned mud), it will be considered "overweight".
Gone are the days though, when you could stick a couch on the side of the road and they would pick it up.
The "proper" way to dispose of a couch is to load it up in your truck, carry it to your brother-in-laws house (in the county where open fires are allowed) and throwing it on the burn pile. Just remember to do it in the late evening to cover up any black smoke that rises.