It's a step down to transition from having top billing, having your name in the show's title, and your face on the billboard, to becoming a bit-part contributor on a competing show. By accepting a less prominent role on a former rival's show, Shannon is lowering his own value.
Even though ESPN and First Take is and always will be a more popular than FOX/Undisputed, Shannon is walking away from being the main guy. He's moving away from a role where he's putting up 25 shots to playing in garbage time, with scrubs that will chuck up their own shots and refuse to pass the ball.
If "IT'S MY TURN!!!" was a problem then good luck with Molly cutting people off, SAS flexing on contributors (Jay Williams, Jalen, etc.), contributors trying to out-clown each other by saying dumbest shyt so they can get headlines.
Shannon Sharpe is a Hall of Famer, top 5 TEs of all time, Super Bowl winner, versatile enough to talk multiple sports and social issues. He is well-known enough to mingle with celebrities and most importantly on a crazy upward trajectory. His podcast was doing huge numbers, with multiple full episodes getting millions of views, even without featuring A-list celebrities. Meanwhile, Stephen A Smith, the host of the show he will now be a contributor on, only managed to surpass a million views once, and that was when he was discussing Shannon Sharpe. That is SAS's most-viewed video on YouTube.
If he was gonna branch out and for example be a contributor on GMA and then occasionally appear on First Take, that would make sense. If he gets his own daytime show after Pat MacAfee Show airs during football season and contributes couple of days a week on First Take that would make sense.
However, for Shannon to willingly step away from being the main host, without any scandal or case of sexual harassment, and to place himself on the same level as the corpse of Chris 'Mad Dog' Russo, who has been irrelevant since 2008, is definitely a backwards move