A major incentive in the design of the combat rifle was a cost-benefit analysis in terms of the expenses involved in the training, equipping, and potential resource loss of soldiers. Better-trained soldiers outfitted with larger-cartridge battle rifles -- even when they are semi-auto only and not select fire rifles, like the M1 Garand -- are more individually effective, for instance, than assault rifles. On the other hand, fielding such more highly trained, effectively equipped soldiers is much more expensive and a greater loss to aggregate military power when they die in the field than the same of less highly-trained, more lightly equipped soldiers. That is, someone who can make full use of a battle rifle out to its ideal engagement range and issued such a rifle is significantly more effective in the field than someone whose skills do not extend past the ideal engagement range for an assault rifle issued such a rifle -- but the former is more expensive, both to deploy and to lose in combat, than warranted by the increase of individual effectiveness, if you treat the value of the soldier's life as nonexistent and only regard the soldier as being equivalent in value to equipment.

Of course, this thinking also tends to undervalue the often substantial value of the exceptional case of a single soldier who can account for a far higher number of lesser-trained, lesser-equipped enemy soldiers from longer ranges, because the capability to reliably perform under such circumstances is essentially prohibited by the strategic decision to issue assault rifles by default and only provide combat and marksmanship training out to around 350 meters to the general run of soldiers. It's the classical mistake of focusing on the statistical averages to the exclusion of considering the sometimes overriding value of the exceptional case.

The American Revolutionary War was essentially won by the exceptional cases, after all (discounting, for the moment, additional factors such as French assistance).