Portable personal radar on helmet with a tablet or wrist thing that says when and where drones are so they can shoot them.

Imagine firing an AGM-88 and it blaps some random soldier setting up a foxhole

I imagine it's due the same reason nobody would like to wear smart glasses which highlight every tick, venoumous spider and the like, crawling around in the forest. You'd be too scared to go into the forest at all. Better to deal with them naturally, as God intended.

It should just shoot the drones by itself

That’s ridiculous, that would lead to mass unemployment in the funeral industry.

Let's add a 60 pound helmet and a 120 pound battery to my rucksack. It will be fine.