#2 Why Chris Jericho should leave: His Star Power is is overshadowing the younger performers in Inner Circle
Chris Jericho's The Inner Circle has had a decent backstory with a number of twists and turns. The storyline of MJF and the coup was also a very entertaining arc to watch. Although MJF has gained popularity, the other current members of the Inner Circle are still overshadowed by the legendary stardom of Y2J.
Sammy Guevara, Santana and Ortiz have all shown potential as future superstars of AEW. The promotion is already oversaturated with stables, and with Malakai Black's House of Black slowly being formed, the Inner Circle will probably no longer be on the frontline.
Guevara is already the TNT champion, and is also starting to feature in the main events on Dynamite. It's only natural that they be allowed to follow their own paths outside the limitations of their stable.
Chris Jericho can also go out with a bang, since he's such a huge part of the show. A credible storyline with a young heel against Y2J would set up a formidable villain in AEW if Jericho retires as part of the story. Someone like MJF could fulfill that role very effectively.
#2 Why Chris Jericho should stay: He has plenty of dream matches left in AEW
While Chris Jericho has tussled with MJF and even had a match with Darby Allin, there are a lot of major AEW stars that are yet to lock horns with him. A full-scale feud between Y2J and other talented wrestlers like Eddie Kingston or Bryan Danielson would draw widespread attention from the wrestling community. This would benefit Tony Khan's organization to possibly gain even more mainstream popularity than WWE.
Although Chris Jericho is not young anymore, he is still a great wrestler capable of holding his own in the ring. His departure would be a great loss since he still has so many wrestlers to interact with in AEW.