I was in the military and it’s not difficult at all to move normally with the 25-50 lbs of gear that these guys are shown with. During my initial entry training for the Army we wore our kit (helmet, body armor, weapon, first aid supplies, etc) nearly everyday. It was over 50 lbs of gear and after six months of that, we could maneuver around as if we weren’t wearing any gear at all. Just because it would be difficult for you doesn’t mean that everyone would struggle in a similar manner.