Earlier quoted context omitted.
Is aging bad though? Seems like natures way of helping humanity evolve. As individuals it may seem bad. As a species, keeping old ideas in the form of ossified biology around seems like a bad idea. For example: see 70-80 year old politicians ageist assault on future generations. Physics is ageist and its march towards entropy unstoppable. Anti-aging is just more first worlders who can ignore externalities thanks to f…
Aging exists because the human body is optimized to survive and reproduce in a resource constrained environment with many threats. Our predecessors eked out just enough calories to survive to the age of 15, when we could begin reproducing. Any traits that made it more likely for us to survive until that point, even if those traits resulted in damage that would eventually accumulate and wear us down after our reproduc…
Humans are a pretty damn care-dependent species. They're not going to defend or feed themselves without years of support, so if they aren't surviving en masse into their 30s and 40s, the next generation is probably going to have a severe die-out.
Beyond that there's probably ongoing marginal benefits to species fitness with longer lifespans. If you can keep a few generations in circulation at once, you probably have greater resilience to things like disease outbreaks (the 50-year-old cohort might have some past related immunity to a disease that rampages the 20-year-olds).
This also completely ignores any value of intelligence and ability to pass down knowledge, which is definitely a fitness factor just for being able to prevent future generations from poisoning themselves as easily.