Using supplemental oxygen for high altitude climbs is common. I’ve even seen people use mini oxygen tanks on Mt Fuji. While it’s highly unlikely you’d need extra oxygen around that altitude (unless you go there with absolutely no training and the lung capacity of a goldfish), it can keep people alive and let them succeed above 8000m.
I don’t know who came up with the idea that climbing without supplemental oxygen is the only “fair means” to reach a summit (maybe Messner?), but I beg to differ. It is definitely a bigger achievement but that does not make using it cheating or doping.
I’m writing this because I was reading Training for the New Alpinism and they literally argue that. Yes: that supplemental oxygen is doping. Which is just ludicrous and extremely irresponsible and dangerous to say from a position of authority. People die at 8000m. Hell, a teammate was helicoptered out of Aconcagua base camp because of pretty severe altitude sickness.
It’s even stranger because they don’t denounce using Diamox for example while unlike oxygen that is actually an artificial chemical. In my “outside” opinion as someone who hasn’t been there (yet), supplemental oxygen is no different than safety equipment or high calorie food. Is it doping if I eat a 600kcal bar at altitude? Of course not. (It’s another problem whether I can actually digest it at that point.)
Going for a 8000m summit strictly without supplemental oxygen (maybe not even carrying enough for emergencies) sounds similar to free soloing. It’s a great achievement but the risks are just out of proportion. Personally when I’m going to climb a 8000, I’ll try without supplemental oxygen. But the moment a guide or sherpa (or my body) tells me it’s oxygen or going down, I’ll choose the former without hesitation.