If the “natural lifespan” of humans ends to be 38 you are using a flawed definition of natural. This also connects to people believe that humans in the past die

If the “natural lifespan” of humans ends to be 38 you are using a flawed definition of natural. This also connects to people believe that humans in the past died with 30 latest because the life expectancy was 26 years, ignoring that this is an average heavily influenced by child mortality