Dennis Schroder is just looking for a bigger contract than what the Lakers is offering him, perhaps he just want to maximise his potential while he is still healthy. But obviously, LA doesn't want to provide or at least they don't have the capacity right now to offer it to Dennis because of salary cap.
Staying at LA is no longer good for his career, with LeBron and Westbrook in front the rotations for him might be harder, he won't gets good minutes with healthy King James and WestBrook, Better to find another team since he already decline the extension of his contract.
Knicks already have Kemba Walker recently acquired, and they have Rose as well, if Schroder goes there, then they have a 3 guard rotation, not sure if that is a good idea. Unless. they will get Schroder and then trade him again.
Might better to think deeper for the knicks they need big players and role players not a star quality individual, Kemba and Drose plus Barrett and Fournier good enough for the frontline.
They need back up for Randle Big Man who can create and deliver inside, it will give more space for their shooters if they've got options inside.