I guess that's why all major militaries are running iron sighted, slick rifles and disposing of their optics and suppressors. These accessories are the force multipliers to the infantry, which for many militaries is a carefully husbanded resource that is difficult to replace.
Most have chosen the optic as best return on investment since it gives infantrymen much more reach for detecting, identifying and engaging targets. Optics not only increase reach and precision of fire, they also reduce training burdens. Yes, you do teach iron sight usage but almost all BUIS is worked around a battlesight zero and there really isn't dialing range taught anymore.
Suppressors are universal in SF because they offer so many benefits for not so much weight. Eliminating muzzle flash, significantly reducing recoil and audio signature means you are much harder to localize after you start firing. If they can't find you, they cannot take you under effective aimed fire. The resistance to suppressors for the infantry is based on pure ignorance.
Clip on NightVision/Thermals. That forward top rail today is meant for an in-line night vision device that lets you use your optical sight. This means your reticule and zero do not change. A helmet mounted NOD cannot be used to aim with any magnified optic.
Any one of these accessories is a decisive advantage over an enemy that does not have it. If every time my infantry engages the enemy and wipes them out without been spotted or localized for return fire, the enemy is going to have a severe morale problem long before he runs out of infantry.
biggest thing at the moment is night vision and the training to use it effectively. At night you can run circles around the enemy and he does not even know.
Also suppressors shine at night or rather do this exactly not. They reduce the signature of the muzzle blast and also make communicaiton within the unit so much easier, when you do not get blinded and deafened by your own or your comrades firearm discharges.