[jimbokun]

We are on course to have far more elderly people than young people.

A global retirement community without even any grandkids to visit them strikes me as a depressing dystopian future.

[foobarian]

The question is what happens after they are gone?

[littlexsparkee]

I see less burden on earth's environment as a positive.

[jurgenburgen]

More likely it will be a larger burden on the environment. If there are no future generations to care about then why bother investing in a better future?

[ionwake]

not necessarily connected to the number of people but the type - if they are all conservationists that would be a net positive, not counting OTT population numbers.