I'll keep this short.
The unit absolutely eats the dust against axis in the early game -especially because of the map pool. (Edit : Wording)
Early game,
You get beaten by Volks and Grens at long range.
You get beaten horribly by Volks and Grens if you decide to charge at them.
You beat Volks marginally and beat the Grens handily at close.
Which both cost less than the rifles and has access to their weapon upgrades without any side techs.
The issue is compounded even more when you consider the supporting units of axis factions:
Against OKW:
***Sturmpioneer eats your rifles and your measly Rear Echelons for breakfast.
***Kübelwagen bleeds you to death from range.
Against OST:
***Pioneer does better than your Rear Echelons, provide good support to Grens if you decide to charge them and provides sight to MG42 which you don't have any counters against unless you go for sidetech + leuitenant/captain/your rear echelon with your rifles or the worst mortar in the game (which also creates another weakness with sub-optimal build)
***MG42, mentioned above.
***Sniper, that is literally uncounterable without Pathfinders or LV (Captain one, which is the meta, arrives too late against sniper aswell).
In the end, Rifles are much more micro-taxing and annoying to use while their performance is gated extremely behind veterancy and sidetechs. I don't know if any more updates are coming to the game but if there are, then I hope the rifles are addressed.
It seems to me that you are exaggerating. Riflemen is a very strong unit. Can 1v1 Grens at any range but long. And 1v1 Volks at any range any day of the week.
Riflemen are very versatile and can be equiped with Bars, Zooks or 1919s according to the game situation.
The only real problem are Kubels and SPios. But hey, cmon, 2 blobed RM can easily force them to retreat.