Innovation relies on bigger groups, which then allows a smaller portion of the population to do more.

While I tend to agree with you, I find the Japanese are incredibly innovative and they are not growing. Maybe I should look at the rate of innovation and see if that has stalled out with population growth?

Perhaps.

To me it feels like their most rapid period of innovation was post World War II as the population was growing very rapidly.

Which major disruptive innovations have come out of Japan lately?

Not major disruptive innovations, but the gadgets that do all kinds of little quality of life things. They have innovative solutions to so many of the small things in life. And a society where you can invent and bring to market quirky little products that do cool stuff.

I have heard this before...in what sense would adding population result in more innovation rather than having a more supportive environment for the people we already have (healthcare, education, financing, etc).

Simply more nodes for experiences to bounce through, so long as they have ways to communicate enough to copy, recombine, and incrementally improve on their activity. The more people copying, recombining, and improving on stuff, the more innovation.

Often easier to consider this in terms of competitive sports, though you could check seshatdb or something to see if it holds at scale. For example, YouTube really changed a lot with sports.

You figure our society is "increasingly extractive and unequal"? That may be true relative to post-WW2 America, but on a larger scale--either historically or geographically--can you really hold that modern society is more extractive and unequal than slave societies, serfdoms, and empires of the past?

Honestly, population growth has, if anything, correlated to increasingly equal and egalitarian societies.

  > has, if anything, correlated

This phrasing is delicate. Correlated, but likely not caused by nor a cause of. Just two things that happened in parallel.

To be clear, I am agreeing with you.

Wealth inequality in the USA today is worse than 1789 France https://populareconomics.substack.com/p/is-wealth-inequality...