I dunno, from both having worked in a few food service jobs and as a customer, I think it's a bad idea.

Any fast food joint, the trash cans are in the seating area. I promise you that people are idiots and will screw things up, even in nice restaurants. You have no idea how careless people are, even when they're otherwise very nice and respectful. And you have accidents, which the customer isn't equipped to handle. Many a time back in those days, the front staff would end up doing more work cleaning up problems from people honestly trying to get their refuse in the right place than they would have if they'd had to clean the tables themselves.

At a regular restaurant? You've got plates, cups, silverware, and all of that has some degree of food waste on/in it. The nicer the place, the nicer those things are. Can you see how much chaos and expense there would be in each table of customers trying to carry their stuff to a drop off for the items, and get rid of trash/food waste? Nah, having staff do it is less expensive, better organized, and less likely to cause lawsuits.

Besides, cleaning isn't degrading. It's just a job. Doesn't matter if you're cleaning at a restaurant, a home, or someone's ass (hello fellow nurse's assistants!), you're doing a good thing that harms no-one, and helps someone. That can never be degrading. A given employer may be degrading, but that's a different thing. You can run into jerk customers that try to make it degrading, but the work itself is just life.