That is the lie. The first benefit is removing a President who has demonstrated he is an actual, factual opponent of Putin. Trump smiles and pretends friendship, but acts in America's interests FIRST every time.
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On the record: The U.S. administration’s actions on Russia. Tuesday, December 31, 2019"
On the record: The U.S. administration’s actions on Russia
The second benefit is replacing him with a Democrat "cypher," i.e. by a Party now focused on (IMHO) the internal sabotage of American "exceptionalism" in hopes of gaining long-term political control.
A Party whose leadership has already demonstrated tactics of "appeasement" internally (i.e. literally "bending the knee" to Socialist elements here), and while "talking tough" bodes to repeat the prior Administration's lack of actual action.
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President Trump is tougher on Russia in 18 months than Obama in eight years" Jen Kerns, 07/16/18
President Trump is tougher on Russia in 18 months than Obama in eight years | TheHill
I'd say Putin hopes Biden is elected to office, so anything that damages Trump is a positive in his eyes.