The Golden Knights will be fine without Mitch Marner
There was a point in time where the Vegas Golden Knights could've used a talented winger like Mitch Marner. An offensively dynamic player of his caliber would've elevated the team on many levels, ranging from the power play to the top line. Plus, the Golden Knights would've gotten a younger, bigger player to replace Marchessault.
However, that time has passed and the Golden Knights don't need him anymore. Even with a projected $5,524,395 in deadline cap space, the team has other needs. For example, they need a shutdown defenseman to replace Alec Martinez's production.
Granted, moving pieces around will be tough, especially with Shea Theodore and Brayden McNabb extended. However, getting the 27-year-old from the Toronto Maple Leafs isn't so much of a priority now. Eichel will need a contract extension himself, with his deal expiring after the 2025-26 season.
Meanwhile, the Maple Leafs are contending and will look to acquire pieces themselves. There's also the strong possibility they could look into extending their superstar winger during the offseason (or regular season). Therefore, it's best to move on and refocus efforts on building defensive depth.