I am not so sure any comparison is straightforward. I have never climbed mountains anywhere near as high as Everest, but I consider myself an alpinist. What I think is safe to say is that the accepted level of risk and exposure in mountaineering is _far_ higher than in diving. Divers will mostly consider a plan not viable if at any point the answer to the "what if?" question is "we will die, end of the story". Even in casual mountaineering, there will be situations like this, and not very rarely. And this is still comparing the relatively casual, happy side. Do not think about rich tourists on Everest (by the way, it still is not an easy walk to a selfie, this I am very sure, it will still be weeks of continued strain and also suffering), but think about Messner 1980, all alone on the Mountain, during monsoon, going without oxygen and alone on a partially new route. I honestly can not even think of something remotely as daring ever done in diving. I personally think this Everest of diving has not even been discovered, much less climbed...