3 reasons Madison Bumgarner doesn't make sense for the Cubs: There's no room in the rotation (which is a nice problem to have)
For the first time since Chicago was at the peak of its contention window a half-decade or more ago, the starting rotation is a position of strength - at least early on in 2023. Both Marcus Stroman and Justin Steele are looking like real front-of-the-rotation pieces and Drew Smyly and Jameson Taillon are solid rotation mates, along with newcomer Hayden Wesneski.
Knowing all that, the Cubs already boast a full rotation, and one of their main starters, Kyle Hendricks, is not even back from the injured list yet. Not to mention there is solid pitching depth throughout the minor league system ready to fill the spot of anyone who goes down via injury.
The Cubs could use a true ace-level starter, but Bumgarner has not been that guy in a long time. Unless he wants to be the lefty specialist out of the bullpen, a position the Cubs failed to address in the offseason, Bumgarner just simply would not fit on this team in terms of a roster standpoint.