This is Standard Soviet Play (albeit well executed). Once Soviet's have Snipers + Su-85 its gg. Germans need to win in early game or OPEL Strafe Abuse to have a chance late game.
The root of the problem is no German Hard counter to Sniper + Su-85. The Halftrack provides Soft Counter to Sniper until Katyusha which prevents blobbing and effectively kills your soft counter. In fact, the Kat was the turning point of the game because it marked the dominance of Sniper + Su-85 (the snipers had a total of about 80 Kills).
Relic needs to take a hard look at the German Sniper. You shouldn't need a VET 1 German sniper just for it to finally be able to act in a counter snipe role against a VET 0 Soviet Sniper and die when someone sneezes at it.
I agree with you, the late game 3xsnipers and 3 su-85s was too much, my infantry died instantly and i think if i had turtled a bit more, get 1 more panther, i might've had a chance. well that's that.