Of the big 4 sports, NFL is the one where you can turn it around the fastest since the draft is 21 years old and older. But, that's mainly dependent on the QB. Chi, Was, NE have a chance to turn it around with their QBs. Denver, have the right HC to work with a tier 2 QB. Penix and McCarthy TBD.
That and drafting well for 2 drafts can really change your roster. Seattle hit on Cross, Mafe, Walker, Lucas, Woolen, Bryant in 2022 class, though most haven't played as well since rookie year save for Mafe and Walker, then Cross. But, if you stack a couple of classes like that, you can really turn it around fast.
MLB, lots of time as even an elite hitter only gets 4-5 chances to hit a game. And you need starters and relievers for P.
NBA, star driven. Most teenagers need time to find their game, so don't expect immediate turnarounds with a couple of top draft picks.
NHL. Like MLB, NBA, drafting teenagers and their development over the next 2-3 years is out of your control as they play for their club teams until they arrive in the A or NHL.
Thus teams are more likely to ride their top guys until the very end. Before you even think rebuild and selling off your top guys, have you done a full evaluation of your scouting dept? What have they done for the team over the past 3 drafts? Make sure you build up that group because if they've added little to the organization in recent years, not suddenly going to turn it around moving forward.