I'm not sure what you mean by fairly recent. On the surface, I would argue that's it's been a reasonable and common expectation since the time of the Enlightenment and the Industrial Revolution. Been a pretty bumpy road with dead ends and detours.So what’s the implication of that? That you shouldn’t care or try because you won’t be here to see it? It has been a fairly recent phenomenon for people to expect a better standard of living in their lifetime, but that didn’t stop people fighting for it.
You could even say much of it started when the Black Death created such a labor shortage that serfdom ended and the rise of a middle class started.