If Axis elite infantry were nerfed then Allied elite infantry would certainly need the same axe to befall them.
All elite infantry have ridiculous DPS. A single Thompson Paras/Rangers or Shocks beating 2 Axis squads is the norm, while Commandos need to ambush to pull that off.
Elite infantry need that superior cost-effectiveness because they usually have no snares/utility and come out much later versus already vetted and/or upgraded mainline infantry. They also have smaller windows of effectiveness because light vehicles are already hitting the field and medium vehicles will follow soon after.
The reason you think only Axis elite infantry have super-high dps is that you only play Allies/USF.
Obers and Panzergrens out class Riflemen but what do all three of these units have in common? They're all non-doctrinal units. So you have standard Axis units that will outpreform USF units despite the claim "Allies (especially USF) have better infantry". So the truth is USF doesn't actually have better infantry at all. The only exception is doctrinal Paratroopers, I don't think there is a better infantry unit in the game but that's limited to Airborne or Recon.