the server and busser will 100% stack them and grab them by the edges of the plates to keep their hands clean, plates generally arent 100% level surfaces and fully covered in gravy so the issue youre imagining doesnt exist

I don't understand this. At all. Do you let them seat you at a dirty table? Do you think they don't wash the bottom of the plate? Are you and everyone you eat with flinging food everywhere and somehow getting food on the bottom of plates from the clean table? Please explain it to me.