I'll grant you much of this. Yet, I would also say that it is still possible to do better without having to make everything Super Complicated And Nuanced.I think that one of the draws of fantasy games is often the more simplistic and child-like depiction of good vs evil, wherein good guys beat up bad guys because that's what good guys do.
Obviously, in the real world things aren't so simple. To even know where to begin we often have to examine the philosophical or religious lens through which an individual views the world. Something that is good from one perspective may be evil from the perspective of a different moral framework.
Is barging into the warren of a bunch of goblins who were minding their own business, slaughtering them, and taking their stuff, the act of someone good? From a real world perspective it's extremely colonialist, and that's arguably the most positive thing I can say about it. But from a simpler perspective they were "bad guys" who were going to commit evil at some point and therefore stopping them is a good act. Even if, here in the real world, we recognize that as overly simplistic.
At my table we're all adults who know better, but for a few hours a week we like to forget about the complexities of the real world and return to a more simplistic and child-like view of what good is. So we don't generally worry about that stuff. There's nothing wrong with a little escapism.
The point being that good, particularly in the context of a fantasy game, is relative. And that good characters can absolutely shoot first and ask questions later, depending on the style of game you're playing.
It's part of why, in my home game, I chose to go along with the Zakhara concept that nearly all sapient beings are welcome in society. I haven't actually had goblins (or gnomes, or a handful of other options) show up in-game yet. But there have been ogre caravanserai owners, minotaur vendors of fine dishware (), orc librarians, etc.
When people are bad? They're bandits and outlaws, just as you would if every sapient being were human. You don't have to make a big production of it. Just show what bad stuff they've done. If the players want to run it as a "justice for wrongs done" thing, they can--that's up to them. (Though they might want to think about what message that sends.)
And if you want enemies that can just be KOS zero thought required, well, that's not that hard. Vampires and ghuls make a great "sapient but evil" option, where killing the literal undead is straight-up a kindness to the poor soul trapped so. Mind flayers are another great choice, as are things like invading alien beings or Far Realm entities (or just stuff cribbed from Eberron, if you like; those guys are nasty.) Liches. Slavers actively abusing and/or killing their slaves. Etc. There are plenty of things you can do that are really obviously not okay, without having any amount of "hey...is it okay that we're just killing these goblins simply because they're goblins...who were living on this land...?"