Thank you for explaining. Could be he's a misanthrope, through life experiences or such.

I share the same sentiments as you, it'd be a tragic loss. But saying they'd "end" is well, unlikely. The countries will shrink. Japan population could reach 60M by 2100 if nothing is done. That's still a lot of people and by then other factors will dominate and fertility may rise again.

Humans are adaptive and a lot can change in half a century, so I would not overly index on what projections say. Everything would need to stay static for the projections to matter, which given the rate of technological changes and geopolitical tension, sounds likely.