Here's the reality.
It cannot fail in the field, for example, if your 200 lb power armor stops working for whatever reason, you have to be able to carry it out... and over anything, keep it from being used by your enemies, otherwise it's no longer an advantage.
Going off of that last analogy, when you are talking about regular infantry, you can have all sorts of technology and advantages, but the idea is to only be a few steps ahead of your enemy, because infantry is and always will be fodder, you will lose bodies, and everything that body was carrying, to your enemy. Your enemy will use everything they find.
A self-destructing suit is something to consider, but if your enemy is smart enough, they WILL reverse engineer, also, people are real touchy about getting back the bodies of their beloved soldier.
The reality, as boring as it sounds... Chemical enhancement and advanced vetting/training for combat soldiers is much more likely, if you can't risk loosing valuable technology, you can always make a better soldier. Which is why our current infantry is still using rifles that SF was using in Late vietnam, and why some of the rifles used in Afghanistan had also seen action in desert storm. Also why the oldschool ceramic armor is still used.