Upload & Sell: Off
It is going to always come down to the two big things: what is the main purpose; and (ii) how finally, undisputably significant is weight.
For climbing, I don't do it, so I can only imagine for mainly vertical activities very light is very important even if the purpose is to shoot good (e.g. salable) images.
For the other things - o/n or m/day hiking, trekking, 'walk up' climbs (which go to 6000m some places), even for fine photography pursuits, weight does matter to a point, but not much more than as one input of many.
Most such people carry around 25-30% of body weight in good comfort, unless they are weight weenies who take things like half size down bags and tarps for shelter, and eat just noodles for days, bludge off others and walk out miserable and emaciated, with a starry look of achievement in their eyes, lol.
So the average fit guy might scale in at say 80kgs, so he is looking at 20-24kgs total payload.
If conditions are harsh, if you want creature comforts a little, and the trek/walk/climb is say 5 days or more, the gear weight adds up fast, even if you are the parsimonious type.
Me personally, I carry 1600 grams of lenses, 1000 grams of camera/batts, and a 1600 gram tripod and head. It is 3.6 kg, or for the metric-challenged, around 8 pounds. I think the gear delivers better image quality than any small camera/lenses by quite some margin (bar one, see below), this is FF DSLR plus Zeiss, good pod/head for low light/time exp...and it all amounts to, in percentage terms:
16% of carry weight, and 3.5% of total body/carry weight. Does that sound too much? I mean I shoot for approx the best quality short of medium/large format, and I don't think it is an excessive load to carry.
It's actually a real pleasure to have enough food to stay 6-8 days in a location, a general area, as the serious work takes serious amounts of time - waiting for the light, learning the environment, seeking out compositions...I would not want to short change myself and be looking over my output in years to come, and be disappointed at the IQ, lack of crop ability, large print ability, lack of resolution.
So that is another view into it, and why landscape guys haul their stuff rather than take a tiny compromise pocket cam. It's also why the RX1 is such a desirable camera, and I hope for an ILC version - because *no one* likes to haul more than feel they have to.