In the 20th century, the population of horses (in the US) started declining rapidly, from a high of over 20 million in 1920 to under 5 million in 1960. Industry decided the horse was unnecessary after thousands of years of history, thus they were slaughtered in short order.

The only difference between me and a horse from the market's view is that I do different jobs and consume human goods. To the extent that I am necessary it is because the market will need someone to move goods and services to, but left to its own devices it might well decide to sell weapons that I get killed with. Markets are honest, not smart.