They didn’t just get Evander Kane. They got Zach Hyman, Ryan McLeod, Jay Woodcroft, Evan Bouchard, and a bunch of other players that made an impact. You can’t add all of those pieces in just 1 year unless you have a pipeline to draw from.
Also, it’s pretty easy to say “just throw all your first rounders out to improve the team now”, but what happens if we don’t win anyway in the next 3 years? We have no one to call up for cheap depth in the playoffs (Holloway, Broberg, etc), no one to fill in once some of our older players move on or get reduced roles, and our team is completely devoid of talent if McDavid and/or Draisaitl choose to leave, god forbid.
What is convincing the big guys to stay if they don’t win in the next 3 years and our cupboards are all but ravaged and destroyed?