But in terms of real products that affect people's lives in positive ways, capitalism has a problem. There are going to be fewer real people in the future, which means a shrinking market for everything, which makes it harder to justify technological improvements and amortize their R&D costs over a large market.

I thought the US population was predicted to peak in like 2080.

Also, hasn’t per-capita consumption in real dollars gone up way more than 10x over the last century? So even if the population in 2126 is slightly lower than in 2026, people’s actual consumption could be much higher.

What am I missing?

The peak has been moved up by decades in the last year. The 2080 figure is from Nov 2023 [1], before Trump administration cuts in immigration. The Jan 2026 CBO report predicted a peak of 2056 [2]; a similar Institute for Family Studies report from July 2026 [3] predicts a peak in 2054.

The delta is entirely because of immigration. If you count only natural fertility (births - deaths), population growth nearly went negative during COVID (distorted somewhat by the high death rate), briefly recovered, and is predicted to cross again for good in 2030. The Trump administration's signature campaign promise is to clamp down on immigration, and even get an estimated 12-15M illegal immigrants to self-deport. If this happens, the population will immediately shrink. Immigration and immigrant families are what is propping up the population; if you assume net-zero migration (which IIRC was one of the scenarios modeled in the Census projection), the population already peaked in 2023.

[1] https://www.congress.gov/crs_external_products/IN/HTML/IN123...

[2] https://www.cbo.gov/publication/61879

[3] https://ifstudies.org/report-brief/the-demographic-dead-end-...