It is unfair to straight up compare Volksgrenadiers to Conscripts or Grenadiers.
OKW has been designed with worse support weapons, so Volksgrenadiers are meant to be able to fight better independently than their counterparts. They are meant to be slightly more cost effective than other infantry.
Conscripts and especially Grenadiers however, are designed to be supplemented by support weapons.
worst support weapons :
mg34 : a mg 42 just with lower stats same arc
leig : pack howie 2.0 cost almost nothing (so spamable where the howie cost a bunch to unlock and a bunch to produce in a team where rifle cost already tons of mp) can be use with 2 model (howie need 3 or he die) and get doctrinal firestrike.
raketen: at gun with camo and retreat you can scout shoot and retreat, cost nothing (the cheapest at in game so you can make 2- 3 of them together and roam the battlefield)
so yeah really worse collective weapons