If the USA had not supplied the USSR with materiel the USSR would have collapsed in 1942/43
If humanitarian assistance was given but lesser military aid then the USSR would have collapsed.
Bluntly, without American manufacturing prowess, the USSR stood no chance against the Germans
I do not agree with this either/or conclusion, as I believe it would have been possible to provide the USSR with enough help for them to push Germany back, but not so much that they become such as advancing army that they took Berlin first. However, there was a possibility of Stalin making peace with Hitler, which would be bad for allies.