alt Hacker News> if factories are still producing things like they were 20 years ago, the CPI would have been much higher, and that higher number is closer to what should have been the inflation number
This is an impossible counterfactual to test. In reality, tracking value across time requires adjusting for immeasurable preferences. This is why inflation is really only a useful measure for personal purposes across periods of years. It’s only macro economically interesting across a generation and close to meaningless longer than a human lifespan.
I think it's so obvious that no testing is needed, but generally I don't disagree with your take.
The thing is one really needs to understand what "real yields" mean when investing in bonds, i.e. it means your purchasing power with respect to cheap commodities tracked by the CPI is preserved, but it doesn't necessarily mean "value" (whatever that means in the abstract) is retained.