I haven’t read the current rationale but one thing I’ve read is that Everest is _crowded_. This is OK when everything is moving along ok, but when something goes wrong it can be catastrophic for the climbers in front and behind you. I imagine it’s likely that solo climbers have higher incidents of accidents on Everest than group climbers.

As far as why waste money.. if you are asking that question in earnest there’s probably not a rationale that could convince you as to why. So I’ll abstain.