CBS had been hoping that Super Bowl 55 would be a down-to-the-wire nail-biter between the Tampa Bay Buccaneers and the Kansas City Chiefs. Instead, the game turned out to be a lopsided victory for the Buccaneers—which resulted in the smallest overall Super Bowl audience in 14 years.

https://www.adweek.com/convergent-tv/super-bowl-55-ratings-fall-15-with-96-4-million-multiplatform-viewers/