The life of a major league catcher is incredibly difficult. They are the only players that have to worry about every facet of the game. They are charged with the duty of defending behind the plate alone. In order to avoid pass balls and wild pitches, catchers need to build the trust between their pitchers. On top of all of this, they are also responsible for not being an automatic out at the plate.
Despite manning such a demanding position, ironically, it’s tough giving them a day off because they have these relationships with pitchers. That is why having a solid backup catcher is so important.