Practical concerns altered the way we do things.
When the influenza pandemic of 1918 was over and Latter-day Saints started having Church meetings again, many wards changed the administration of the sacrament. Now, instead of sharing one large cup, everyone would drink the water from small individual cups.
That’s right: If you took the sacrament prior to 1919, you probably drank from the same cup as the person next to you. The Savior instituted the sacrament with a single cup (see Matthew 26:27), and people in general used to share food and drink in ways we would consider unsanitary today. The little paper or plastic cups so familiar to us now weren’t introduced until a world health crisis made them necessary!
For more fascinating historical nuggets, read this article.