The word priority came into the English language in the 1400s. It was singular. It meant the very first or prior thing. It stayed singular for the next five hundred years. Only in the 1900s did we pluralize the term and start talking about priorities. Illogically, we reasoned that by changing the word we could bend reality. Somehow we would now be able to have multiple “first” things.
"Essentialism: The Disciplined Pursuit of Less". Book by Greg McKeown, April 15, 2014.