Exceptions like 10 EUR flights aren't sustainable. They're just auctioning off empty seats to cut costs.
The comparison was conceptual thing to similar thing. Only the rich own and operate private planes, that hasn't changed. The fact that other, more sophisticated planes exist doesn't undermine the point.
There are also diminishing returns. And past leaps in lifestyles aren't guaranteed to continue the same trends, and can reverse.
The earth has seen several major extinction events. Arguably humans are the cause of the latest one. Doubtful we can sustain billions of us without an ecological system to produce our bare necessities, certainly not enough for a full life.
