I'm thinking about the idea of powered armor replacing guns. What would allow this to be possible? 

The obvious problem is that it is vastly easier to build slightly more powerful weapons than it is to build armor to withstand it. Heavy machine guns and grenade launchers would easily be capable of punching through anything small enough to still qualify as infantry. Designing powered armor will have the same dilemma that has faced tank design, that anything with real protection is too heavy to have mobility, which is in many respects a more important part of survivability. Exoskeletons will increase endurance and carrying capacity, but they likely won't increase burst speed. 

One option that occurs to me is that of drone mounted weapons carrying most of the firepower, with the guy in armor serving as a drone controller more than they serve as a combatant. In this case it is more about drones and armor replacing human carried guns than about armor replacing guns directly. The idea of armor is about giving a bit more survivability given that drones handle much of the direct combat and functions that require higher mobility. The reason for keeping people at all is the need to have the "man in the loop" element, for political reasons as much as anything else. 

Could this be a viable possibility, or is there anything else that works as well or better in the same sense?