How can we keep our stuff with us, make it easily accessible and not be slowed down or fatigued by extra weight? Answer: Carry the heavy things on your hips.
Most anglers focus on whether to choose a chest pack, vest, sling pack, hip pack, lanyard or something else. We think of carrying fly boxes, tippet, leaders and other incidentals. But what about the net? What about water, a wading staff, a camera or anything else with extra weight? Carrying these items should not be a secondary consideration. As the heaviest things among your gear, how you carry them is of primary importance.
The heavy stuff is best carried on your hips, so the most critical part of your carrying system is probably the wading belt. And most wading belts are not up to the task.