The sneeze guard is pretty recent
The sneeze guard protects the food from unwanted ejections of bacteria and virus. The invention was a great breakthrough in the protection of food. However, it was only invented in early 1959. It was already 20 years since the first buffets appeared.
It turns out, the inventor of the sneeze guard was a germaphobe, a person with an extreme fear of germs. If it wasn’t for the fear of Johnny Garneau, people today would have been spouting bacteria and viruses to food. It is thanks to Garneau’s fear of germs that this invention continues to protect buffets today. Since the 1960’s, it has now become mandatory.