you cant be evil, nor good, in a video game. simple as. maybe your actions can imitate, what we would consider irl as, good or evil. maybe they can actually affect outcome of the quests, conversations, and even entire story.
but you are still not hurting anybody.
you are still not helping anybody.
alignment systems may try to revaluate your every noteable action, they can try to place you in their n-dimensional charts, label you, but you still havent done anything
meaningful. and the only meaningful stakes can be found in real life - the burden of sins, the suffering of selflessness. good and evil exists exclusively among betrayals, sacrifises, cowardness, greed etc. etc. of day-to-day existence. no amounts of immersion in any interactive media will cover it.
my point is: you cannot simulate good and evil between a real being and an illusion, because it is unsimulable. like love. feeling 'good' after helping a virtual granny find her missing object kitten_04_gray is as delusional as believing these two are actual beings - just because they are made of real particles beaming out of you monitor screen. yet its easier to convince yourself that you 'did good', when in fact, it was absolutely meaningless.
What RPGs can you think of that really allow a player to be a legitimate villain and overall evil piece of shit?
none. my answer is none. it always feels plain once you can see through the paper-thin facade of the medium. sometimes one evil path is written better than an other evil path, but it never feels fulfilling