Ever think about how utterly weird it is, that 99% of video game heroes kill? That eliminating enemies in your way is just a staple of the medium, and it's incredibly hard to sustain an entire game without letting you off at least a handful of sentient beings at one time or another?
Compare to film and unless you're firmly in the action genre, a main character offing someone else would stand out like a sore thumb, and even the majority of the MCU only tend to outright kill evil alien races or overlords hellbent on enslaving Earth.
Back to games, and it's pretty clear killing goes hand in hand with the vast majority of fun game mechanics.
It's so baked into our expectations that people have to actively challenge themselves to "Pacifist runs", and as you'll find out, even the most self-identifying saints can become sinners at the drop of a hat.