OK, so what? Some industries are more essential than others. I'd be more receptive if you leavened the alarmism with links to some statistical references or economic projections. I personally think much smaller populations (like globally 50% of current) would be a good thing for both the environment and humanity in general.
You don't need scientific evidence for everything. These are logical and self evident conclusions. In fact your own conclusion that declining population is good isn't even evidence based. You derived it from common sense, but the missing part is the nuance.
Either way Japan, China and Korea are all in panic mode right now. This is not some speculative issue I'm making up. It's deadly real and there is tons of evidence. Look it up. You're mostly treating it like it is because you're not as informed about the issue.