It's more so that the Soviets are just batshit OP than the Allies. USF vs Ost is fair but unforgiving match up for both sides, same for okw.
All ingame factions should be brought up to Soviets level, not the other way around. The games more fun that way.
USF has a higher win rate in 1v1 and 2v2 than Soviets and Brits do dude. Soviets just edge out in the tournament so far for wins. Basically both USF and OKW got buffed at exactly the same time to fairly significant nerfs hit OKW and Ost.
It's also a function of the fact that Relic ignored a large amount of problems for a long time like Volks having no reason to exist outside of Shreks (partly fixed with Flame Nade, but then you still only need 2) due to extremely poor performance against infantry. MG34 having the worst DPS profile in the game of almost any unit. Flak Emplacement being trash. OKW Panther having a wind down time for no apparent reason. Ostheer T4 costing an arm and leg for mediocre units. The list goes on.