This is the internet/social media era, everything traditional has been diminished in the public eye. Things are only "culturally significant" if they can go viral.
Can you name a sitcom that everyone watches?
Can you name a current pro wrestler with household name recognition?
Are baseball's greatest players household names outside of baseball fans?
How many nightly newscasters or morning show hosts are on the tip of everyone's tongue?
There's no Cosby Show or Seinfeld or Friends, there's no Hulk Hogan or Undertaker or Stone Cold Steve Austin, there's no Ken Griffey Jr. or Barry Bonds or Mark McGuire, there's no Walter Cronkite or Tom Brokaw or Dan Rather, there's no Regis Philbin or Barbara Walters or Katie Couric or Bryant Gumbel. Even the big "names" who are still around with cultural relevance are largely those who started out before social media was a big thing and are basically legacy from that time (LeBron, The Simpsons, The Rock, Oprah, Anderson Cooper, Al Roker).
People need to just get used to the fact that a world driven by social media is going to push culture in different directions than a world driven by traditional media. If you don't like it, then take control back from social media.