All due respect that's overly simplistic and not in tune with the reality of the situation. Taking an elite scoring winger out of the picture and just assuming there's enough B-level talent to make up for his absence is a lofty gamble at best. More than likely you're replacing him with a vastly inferior set of players who will only exacerbate the issue from last year, which was overworking MacKinnon and Makar to the point of complete exhaustion.
It reminds of the time when the cap was first implemented, Boston and Edmonton both let top talent walk to clear cap room because they thought they could just fill the roster via free agency. When they realized there wasn't any talent available, they scrambled like hell and signed inferior players to inflated sums. The Oilers even signed pancake enthusiast Dustin Penner to a desperation offer sheet (and this is coming from someone who actually liked Penner as a player).
I'd be all for letting Mikko go via trade if I honestly believed there was a path to make the team better overall, but that simply isn't going to happen. At best, they take a step back this year and probably next year, and by then--as Henchy points out--the core will likely be too old to contend.
Again, the only way to have really staved off what we're seeing now would have been to draft better, and the Avs are doing far too little far too late to correct that now.