Trump is trying to get Ukraine to agree to something that isn't beneficial to them. Why do you think it's a better strategy to try to browbeat our ally into a bad deal than to try to force our enemy into a bad deal?
But in any event, the "good deal" for Putin will be the lifting of sanctions and the chance to stop throwing away his economy and his people on an unprovoked invasion of his neighbor. Any deal for Putin that involves him still in charge of Russia and not on trial for war crimes is a "good deal" for Putin. Trump can use his tough-guy persona, the art of the deal bullshit, to try to intimidate Putin, not our own ally. The problem, if course, is that he's essentially on Putin's side because he sympathizes more with Putin than Zelensky. Trump wants the level of power and control Putin has. He wants a "might makes right" world order where when he says jump, everyone else says how high. That's the whole problem here.
Any fool can see that allowing Putin to keep territorial gains as a part of a peace settlement - rather than demand he give back the territory he invaded - is a slap in the face to Ukraine and will simply encourage future belligerence.