"ppl usually live on average from 75-87"
Not on this planet they don't. Perhaps in a few rich, Western nations this may be the case. WHO (the World Health Organisation) estimate that even by 2025, only 26 of the world's (richest) countries will have a life expectancy that exceeds 80 years.
Meanwhile, in many countries of the world, life expectancy is considerably lower - for example Sierra Leone, at around 51 years.
But in terms of human history, (let alone geological time) - human life is short.