“I wonder if restaurants have started suggesting that you bus your own table and set the dishes by the kitchen door before you walk out.”
That came with the invention of fast food joints... But in turn it is not customary to leave a tip either. Now that is a fair trade off for our personal labor.
Food to go is what fast food used to be, the trash was your own, if you eat at one of their tables you can throw away your trash or leave it, but tips aren’t for busboys.
I bussed in many restaurants, and we cleaned the tables and washed the dishes and the pots and pans, and mopped the floors at a fixed pay.