I understand that caves were used on and off over sapiens history. We must be sure to temper our view of 'cave men' as a normal mode of living. Caves preserve artifacts, to a much greater degree than open ground or forests for instance. It can be appealing to imagine they lived in caves routinely. But we have little data on the frequency of sites outside caves - they've washed and weathered away. A true ratio is hard to come up with.
And yet, claiming support for a feature doesn't tell all. Different implementations can have subtle differences. Knowing the browser and version can allow a client to survive that.
Soldiers don't use shit. It takes training, preparation, maintenance to use fancy gear. Soldier in theatre are operating on scant sleep, exhaustion, heat etc and have no bandwidth for fussing with tech. Or so my soldier reported from Iraq some years back.
My son reports a burst of 'Jewish' soldiers when deployed. Because the rabbi had a rather long service period and he let the soldiers sleep on the benches.
He still has his camo yarmulke.
They may refuse to learn multiplication tables (a popular subject if I remember right, reciting them as far as we could, a competition) while memorizing baseball stats.
Kids will learn anything that gives them social standing or self-worth in another way, whatever it takes to be a cool kid.