[krisoft]

> Most people can’t breathe at high altitudes due to insufficient air pressure.

Not most people. Nobody can breath if the altitude is high enough. There are some individual variability in how high is too high. That is of interest if you go mountaineering, but not really in a situation where an aircraft rapidly decompresses at the altitude MH370 was speculated to be flying at.

[JumpCrisscross]

> Not most people. Nobody can breath if the altitude is high enough.

Read generously, they're talking about with supplemental oxygen. At 35k feet, even with pure oxygen, many people will not be able to breathe and most will not be able to comfortably. (Above 40k feet, supplemental oxygen no longer works--everybody needs pressurised oxygen.)

(Obviously nobody can breathe above the Armstrong limit, but that isn't relevant with a commercial airliner.)