So honestly the shortcut of “evil species” of enemies is so that you can have throngs of sentient beings that you can kill without having to deal with morality in games. It’s just a shortcut for “Those are the bad guys.” and frankly been going since Tolkien who used it interchangeably with goblins which in folklore goblins were throughout Europe in one form or another which and are typically evil and mischievous for the most part. Weirdly in our RPGs, Hobgoblins seems to be the bigger, nastier goblin but in lore they’re typically friendly, just gonna play tricks. This creating “peoples of evil” is a tale as old as our mythologies.

On one hand, I get it, it’s an easy part instead of trying to be JRR Martin and build a political machine with all the workings and the easy button of “And then the orcs invaded.” I mean, Tolkien did it, I need batches of enemies… uh… “Uruk-hai!” And partially too, unlike “Real Life” us gamers/readers/movie watchers want our bad guys to have motivations that make sense, and complain when someone “acts out of character”… yet we see daily people who get to in charge positions do things that screw themselves up for… reasons? But many people don’t have that issue of “Well, why are they invading? Why can’t we talk them out of it? They should be more logical!” (that last one being frustrating "no, there are some jerks out there you can’t just talk out of a violent situation) when you have them as orcs. This is the “Look, I just REALLY want to have a swashbuckling tale and don’t want to have to think about geopolitics because real life has way too much going on with exactly that.” It’s not a wrong way to play, just a way.

On the flipside… I agree with you that it isn’t interesting in beyond “I need a mook machine” and far more interesting, especially in the right GMs hands, that gives them a whole society. Hell Shadowrun covers that when the goblinization came, SUDDENLY Trolls and Orks everywhere in modern day society, and the age old hatreds of these species can go off… when that Ork over there might have just been a dude who suddenly bulked up, got lower fangs and pointy ears after April 2021. They’re just people, and especially not being long lived and “not a pretty race” to humans, they get treated roughly. Ork social circles are trying to bring back the old ork language from the era last orks existed… it’s fun to have an ork rocker screaming in Or’zet as a yell against the system. This is exactly what you’re talking about, lots of nuance and people are just people.

The third, which I think my group runs into the most is the “evil races” might be used by the GM, but often ignored by everyone, including the GM. Everything from your standard “We found this goblin and he’s our mascot now!” to trying to change a faction to the side of good, to one time because we were playing a one-shot and I was doing a silly bit, my elf was so long lived she was once a BBEG, and the GM rolled with my recognizing a Kobold as a former hired minion, scolded him out of a fight, got his friends together to unionize against his dragon and work for the tavernkeep because she pays better.

Reality of this wall of post is me bringing a discussion to a meme lol, I really hold no opinions about what Charlatans of the Shore doing anything as I’ve wandered off of D&D a few years ago. People are gonna people and if they need a “Light side” and a “Dark side” alignment in their story without a lot of deep discussion of politics/ethics/and philosophy, then having a species of “this thing is bad” removes a lot of complication. Sometimes I want that story the same way I sometimes want junk food, but sometimes I want the dramatic, sweeping plots and the Orc lands are their own tribe of people and the fight is a massive cultural misunderstanding between sides.