if they're sapient, then they can want things other than just to kill people, and if they can want things other than that, then it's possible to negotiate and come to agreements with them.
So many examples from our own history come to my mind right now.
You know you would potentialy be right, IF and only if both sides would be even willing to negotiate ... Take Drow for example, or Githyanki ... no matter the situation, they both see themselves as superior to anyone and anything ... why would they even bother with negotiating?
Oh, I know exactly what you're thinking. And you are quite right. Note that I only said that it's possible to negotiate, not that it's easy or even likely. But Gith and Drow aren't monsters, they're simply part of a culture that won't allow peaceful co-existence with any other group. But that's because of culture, not because of anything truly inherent to them as a species (I might be wrong about the Gith though, I'd never heard of them before BG3). If you raised a baby in some other society, they'd grow up and not just be evil as a function of their existence. A society that's culturally incompatible with others is a different dynamic to an entire species being such.
