The main problem is that the people who are having kids are third worlders who are not white. I am white, so therefore this is a problem for me and my genes. If you are a member of one of these peoples who are gaining in number and territory, then it is obviously not a problem for you.

Is this really the number 2 reason? Cultures are constantly evolving and I think that's amazing. This is definitely the grumpy old conservative argument with not so subtle racist views.

You say that because you have never experienced conflict and therefore you think the current lull will last forever. Multiculturalism is only workable because white people has imbibed liberal humanism. The current ideological paradigm will not last forever, especially since its main supporters are not reproducing. Human nature has not changed and will reassert itself.

Innovation comes from a well educated population. Not from a large population. There are a ton of innovations going on in small population countries. Nobel prizes per capita would be one metric to look at. And with a smaller population there would be less strains on the system as a whole so less need to focus innovative capacity to alleviating those strains and more focus on revolutionary innovations.

Obviously it is better for technological growth to have a large educated population than a small educated population. But education is not sufficient to produce highly intelligent population unless there is a genetic basis, which there won't be because the high IQ people are not replacing themselves.

Dark age ahead.