It doesn't matter if they reach their peak earlier/cheaper, the fact of the matter is that you can't have an infantry unit that loses at every single range to another AND have it be more expensive. Again, Volks can still defeat double BAR Rifles and double Bren sections at specific ranges even though Sections and Rifles are much more expensive.
While I agree that volks late game are the weakest unit... considering who wins/loses
I mean.... one unit will always win. A 120 muni and 280 MP unit has to win vs a 260 MP/60 muni unit. Always. A lot of people think that late game, units have to trade equally until they both have to retreat. Why?
I mean, early on, OKW stats with sturms which can turn the tide since volks:
vs IS: lose long range, hence you need to be the first one in cover or use sturms to 2v1 the IS squad and then establish the foothold and force the brit to assault your cover position
vs rifles: win long range only
vs cons: lose only short range
So early game is quite balanced. OKW has a bit of a harder time, true, so they start with a unit that can shred close range any other mainline unit and trade evenly behind cover at mid range. So you have to survive that period. Then you get your first power spike, that can occur on the field and does not require retreat to base (a big plus) and you start winning engagements.
Then later on, volks become inferior and obers take over as the shred machines. Considering the armour and stuka that supports volks, I'd say it all evens out.
What you could do to volks without breaking anything is buff their vet 5 survivability. In other words, not add offensive capabilities, but defensive ones. That way you can hold your ground for longer to engage stuka or something else to dislodge the attack or make it easier for vetted volks to close in on a covered squad to again, engage something else to dislodge it.
EDIT: If this site is truthful:
https://coh2stats.com/stats/week/1615161600/3v3/wgerman then you can clearly see the 50/50 win rate on 1v1 and a respectable lead in the 2v2 and a massive 57% winrate in 3v3 and 4v4.
If I remember correctly, when OKW came out it was a "survive until later on" kind of a thing. A faction that peaks later
And agree with Carmine. If anything, obers need a buff, not volks.