Always Chaotic Evil fantasy races exist for a simple reason: War is hell; but war is really cool. thus we invent fantasy war that is more morally justified war in our stories (good thing every goblin is evil and endorses every evil act!).
Now, I find goblins to still be a bit too relatable still so I tend towards mindless evil goo in my own war stories.
hm see i understand how this lands you on 'always evil' but how does the chaotic get into it? seems to me having everyone in a species be chaotic adds very little to the justified war thing and in fact detracts quite a lot since now you need to figure out how your always chaotic species coordinates enough to have, like, armies.
is this one of those 'chaotic is an intensifier for evil and lawful is an intensifier for good' things?
iirc, the term comes from old d&d books, where certain enemies (goblins, etc.) would be listed as "always evil" or "always chaotic evil", where "chaotic evil" effectively meant "extra evil".
Chaotic/lawful mostly serves as a scale modifier for good/evil – lawful good will be enmeshed with institutions of stability and justice; lawful evil will be the same but for evil, but chaotic evil will just be causing problems individually