>>2827000 (OP)Correct. The advantage of an external fram placing the weight high up is also an disadvantages when it comes to balance. It becomes top heavy and wobbly when you're leaning forward, like you do when climbing. The internal frame with its more evenly distributed weight makes them more stable and suitable for climbing and mountaineering. Of course everyone want to be like the cool guys climbing big mountains and wants to wear the cool new gear, and so internal frames became the new rage.
The external frame was seen as old and bulky, harder to travel with on planes. Soon people forgot what the fuck an old frame pack is good for.
In the meantime the manufacturers released new technical backpacks with more advanced and adjustable carry systems, trying to figure out how to make these things carry heavy weights comfortably.
With time, some people figured it would be easier to just carry as little stuff as possible. No need to have a backpack that can carry heavy weights properly if you don't carry heavy weights to begin with!