Earlier quoted context omitted.
That's just plain wrong. German PoWs in the USSR had a death rate of 15% to 30% depending on the sources, while Soviet PoWs in Germany had a death rate of 57% to 65% depending on the sources.
Well I don't want to make this into an argument about who was worse but the Russians didn't honor the Geneva convention. The last German POWs weren't released until the mid 50s.
The Soviets did not honor the Geneva convention, as they had not even signed it at the time.
The Germans explicitely suspended its use in their armed forces for the Eastern Front – which is why millions of Soviet PoWs were left to die of starvation in what was basically large cattle pens while Jews or card-carrying Communists were to be shot on the spot after capture.