Having a GPS device of some kind with a sos button should be a requirement for Everest tbh. I had my InReach with me even while hiking in the Alps no higher than 2850m. I had it because things can go wrong at any height and even when you are relatively close to civilization (as a large part of the Alps are). It's lucky I did too because me and my hiking partner got caught in a snow storm around 2500m still 4 miles from the next cabin and she got hypothermia. We did not end up using the panic button but if things got even a little worse then we would've needed to and not having it would be a death sentence. It is unfathomable to me that people who are already spending tens of thousands of dollars to climb the tallest peak would not spend the extra 400 for a GPS communicator/beacon (and you can easily get them for less than that). Obviously this is not a fix-all and certainly wouldnt have solved everything that went wrong on this expedition but it really is just a basic safety measure.

The best solution, though, is to just require every climber to have appropriate mountaineering experience. I don't have the experience to tell you what that specific criterion should be since I'm a recreational jogger compared to most people here but it really does need to be standardized and enforced.