Evolutionary success doesn't mean individual success. The success of the species can be at the expense of individual suffering. Evolution judges everything by the criteria of survival and reproduction, with no regard for individual suffering and happiness.
Does evolutionary success mean the individual gets better? Humans (Homo sapiens) are abundant and conquer almost every piece of the planet. If we say our species evolve successfully, do we now become stronger, smarter, healthier, or even happier?
In Weekly I/O #47.3, we learned that the agricultural revolution didn't translate into a better diet or more leisure. It led to population explosions, but the quality of life for people was worse. They have to work harder with less return. In other words, the agricultural revolution kept more people alive under worse conditions.
Similarly, domesticated animals are also quite successful from the evolutionary perspective. However, if we think about most domesticated animals, like chickens and cattle, they are among the most miserable creatures that have ever lived.
In the author's words:
"Their evolutionary 'success' is meaningless. A rare wild rhinoceros on the brink of extinction is probably more satisfied than a calf who spends its short life inside a tiny box, fattened to produce juicy steaks. The contented rhinoceros is no less content for being among the last of its kind. The numerical success of the calf's species is little consolation for the suffering the individual endures"
Unfortunately, the evolutionary perspective is an incomplete measure of success. It judges everything by the criteria of survival and reproduction, with no regard for individual suffering and happiness.