I appreciate Leonidas' points except that I have to agree with ziggy29: this IS different because diversification is not helping as much as it traditionally has. This time I see bigger, more systemic problems than mere misallocation.
Well, if we're all going down, then that's ok too because we'll all be in the comparatively same spot. A falling tide lowers all boats. You won't need $x to retire any more because $x will go from being 'enough' to 'rich'. Now you'll just need f($x).
Or, we learn to live by growing our own food and we still get by. The only time I'll be convinced that it really is different is when the species is in danger of being wiped out. Otherwise, from a survivability standpoint, mankind will march on.