While I respect your points here, I personally feel that your assessment makes a lot of assumptions and simplifies things to a degree that may not be accurate.
People want to travel to feel fulfilled, because conditions for many of us in the younger professional world aren't simply "challenging" - they're actively bad. We are underpaid. We are overworked. We don't have good housing or lifestyle situations because we don't have the money, the social infrastructure, or the access to services most of the developed world takes for granted. So yeah, we want to change the way things are done, and going elsewhere and seeking out meaningful experiences is part of that effort.
40 hours a week? That's a minimum for many professionals. I don't know a single one who works for a larger corporation and ISN'T putting in 10+ "extra" hours because their workplaces are poorly managed and can't retain labor or allocate it in a reasonable way.
And the whole travel-while-working thing has nothing to do with instagram selfies: we're just never NOT working long enough to actually take a freaking vacation that means anything, so we figure we'd better find ways to work AND travel at the same time if we're ever going to do it. Why would you assume it has anything to do with vanity? Why wouldn't you explore the possibility that there are real, profoundly meaningful reasons that people are seeking a new lifestyle? These assumptions are harmful and block constructive dialogue, which I know isn't your intention at all.
But if we gloss over the fact that current work culture - the 9-5 grind - IS NOT sustainable anymore, we won't get to a place where it IS doable again.