I think "survival of the fittest" is what we're avoiding with civilization. We didn't like having nasty, brutish, short lives where the nastiest people "win". And given our medical technology (and depending how you define "fittest") we can definitely say that people are surviving who aren't the fittest.
Read an interesting article years ago, with a theory re autism - basically, that people who were somewhat autistic used to not get married and thus didn't propagate their genes; but that the rise of computers gave these somewhat autistic people good jobs and social standing, so now they were getting married, having kids, and that's why there's more autism lately.
No idea if that's at all true, but it does show that "fittest" varies over time and depends on the circumstances.
Anyway, I'm glad we have compassion and take care of each other.
I am sorry that so many think of humans as "above" other species and thus think we have the "right" to kill them (aside from basic food needs) and to ruin their environment with impunity. Global climate change is showing us nature may not care about OUR definition of "fitness"