There is an entire generation coming that didn't play baseball, doesn't know the rules, and couldn't name you a team outside of the Yankees and Redsox. Ask them to say one word that best describes baseball and they will reply, "boring". Unless you are a boomer or live in one of the 30 cities with a team, baseball is irrelevant to 95% of the population.
Edit: Not to mention the sport hasn't had a recognizable or marketable star since... Jeter? A lot of the best players don't even speak English or are limited to the point they need to speak through an interpreter. Meanwhile, Manfred thinks gimmicks like Player Appreciation Weekend with the godawful jerseys and corny nicknames are going to turn it around.