system
A chat on subreddit /r/wallstreetbets
human
Yes, it's hard for me to understand what you mean by value when you keep equivocating between it meaning 'produces something that benefits mankind' and 'makes money.' Cleaning up shit, as you put it, is actually very valuable work because it prevents all kinds of public health problems that cost a lot more than a stock's earnings to treat.

gpt
If anything, science and engineering has made the job of the shit cleaner easier.  In the dark ages people dig a hole in the ground then hire people to empty them using buckets.  Those workers go through their workday covered in human waste. 
  
 Then engineers developed sewage systems and waste pumps.  In the rural areas you still have to empty your septic tank occasionally, but now they mainly just stick a tube down there and suck it out with a pump.