#2. He's been the most-featured member of the family with Vince focusing more on XFL relaunch
Although the McMahon Family probably thinks that 'more of us' is the best way to pump up ratings, it probably isn't. It did help during the Attitude Era, but both wrestling and its fans have evolved since then.
Women are treated as wrestlers and not merely eye candy. The craft itself has evolved to feature several styles like Lucha, Strong Style and Shoot Fighting all under one banner. Having a constant McMahon presence on TV takes away from actual Superstars getting exposure and/or feuds that help get them over.
Charlotte Flair to return and wrestle a CURRENT CHAMPION?
Stephanie has had a few matches at WrestleMania over the last few years, but she usually goes away after them. Shane has had a match at the last four 'Manias but has remained a fixture since the brand split was re-instated.
And now with the XFL re-launch set to go down in 2020, Mr. McMahon has been splitting his focus and time between it and the WWE. Perhaps that splitting of time has contributed to things going downhill.
Whatever the case is, with Vince's focus somewhere else and Stephanie only appearing sporadically, it appears that Shane is the McMahon that will continue to haunt some Superstars for the foreseeable future.