That's a "hot take" but entirely wrong. All three of the major allies (US, UK, USSR) realized they needed each other, hence lend-lease [1], the "Germany first" policy (defeat Germany before Japan) [2] and the Malta conference [3].
Without American equipment, the USSR would not have had the supplies to push the Germans west. Without a Russian front, the UK and the USA might not have been able to dislodge Germany from Europe, and the UK may have fallen [4]. Without Britain in allied hands, it would have been vastly more difficult for the USA to stage D-Day, and they certainly would not have been able to provide the fuel for their logistical needs via the Pluto pipeline [5].
If the U.S. Navy had been tied up in the Pacific, I think it’s tough to say what would have happened on the eastern front. The Soviets were pretty dependent on U.S. aid for food, trucks, planes, etc etc. If the naval balance were shifted a lot, that aid might not have made it.
Hopefully, one of the good things that will come out of the Russia-Ukraine War is the eternal shattering of the smug "Ha ha Americans, everyone knows that it's the Soviets that beat the Nazis" notion. Setting aside the total complicity of the Soviets in helping the Germans to dismember Poland in 1939 and attack themselves in 1941, without massive American and British aid Moscow would have fallen in 1941 and the Soviets would have sued for peace in 1942.
