An argument made on such vague terms is easy to make. You never qualified how you measure intelligence, nor which people you're talking about (those who in the past who were wealthy and well-written enough to leave records vs the 'common clay' of today,) nor have you said which cultures you believe to be on the cusp of collapse, nor any prediction of the cause of such obviously imminent disaster. And of course, no proof that it would be a disaster, rather than a mere rebirth.

So I would argue that the provider of such an unenlightened exposition is not in a position to be giving such analysis in a meaningful way.