I think the hoped for end result is that every soldier wears one of these. If only a fraction of soldiers wears one, the ones wearing one will have to keep the

I think the hoped for end result is that every soldier wears one of these. If only a fraction of soldiers wears one, the ones wearing one will have to keep the others informed about the things they see that those without can’t see (and that includes telling them such things as “don’t shoot them. They’re ours” or “don’t go there. It’s a mine field”). That’s a huge efficiency loss, even ignoring that the enemy will start targeting those wearing one.