“Write a good secular holiday tune, one that is not limited by very specifically religious imagery in the words, and you might have a perennial hit,” says Larry Starr, professor emeritus of American Music Studies at University of Washington.
https://www.cnn.com/2021/12/16/entertainment/holiday-christmas-music-popularity-cec/index.html
Songs like “White Christmas” and “All I Want for Christmas Is You” have been popular for decades, but music scholars and industry experts note that there isn’t just one formula behind their success. Various factors play a role in making a holiday song a lasting hit.