To me 'evil', well at least evil for the purposes of this argument, has simply implied a strong degree of self-centeredness at achieving one's goals with a disregard for the negative consequences of one's actions, or the adoption of goals featuring implicit or explicit harm to others.
Honestly, I think most writers and game designers have trouble separating ethical or moral 'evil' from personality types. The 'evil' gameplay choices I see in games, including titles like BG3 (which I will reference repeatedly here, with potential spoilers) range from over the top comic book villain type pseudo-satire, to those with hosts of personality disorders that would make them marginally functional people outside of combat scenarios.
Mostly, the choices presented in video games aren't reflective of any character I had in mind when I started and I'm often less trying to pick the least stupid of a bunch of stupid options, or missing out on tons of content because I refused to let the actual villan wax poetic about their manefesto when I could be putting them down instead. To reference example again, I barely got to hear Orin or Gortash talk in BG3 and missed a few entire cutscenes because they were obviously wackjob turdstains and I had my 'evil' party annhilate them with extreme predjudice and no regard for collateral damage (Orin died in one round and wasn't even able to transform, while no one survived Gortash's corronation). Likewise, I was playing as the Dark Urge, but even as a blatantly evil protagonist, there was no way I could envision my character siding with Bhaal. Remember this is the guy who got stripped of his divinity for botching a smash and grab, who, while fancying himself the lord of murder, was himself murder by some peasant weilding another petty immortal cosplaying as a sword. My character was never in a million years going to side with Bhaal, not because he was good, but because Bhaal was a pathetic poser and my character, indeed most any random slob, could do better. I had my Durge kill every single character that even smelled like they might venerate Bhaal just to give that bum and his church a taste of their own medicine from someone with fewer rediculous pretentions.
What my characters mostly didn't do was go out of their way to kill random civilians, pick on refugees, or be overly stingy with their unlimited resources. Someone asked for money nicely, they got the biggest option available (party was killing so many rich people that they could scarcely carry all the loot) and sent on their way. Someone was rude, or had the misfortune of being between my group and the target of their collective ire they got turned into a smear of gore or a vaguely human shaped mass of charcoal. The flaming fist were generally rude, so they were forcefully disbanded by my group.
Most of the 'evil' options were simply insane; my group was as evil as it was going to get, but were neither weak nor stupid...which all but
ruled out siding with the elder brain, the emperor, any of the Three, handing over the crown to anyone, allowing Raphael to live, or most of the 'evil' options other than annhilation. The developers seem to think that evil is some sort of gentiles club where villians get together to smoke, compare notes
, and laugh manically at the plight of their lessers
. That's not evil, that's just a board meeting at any given publicly traded corporation. The main option that I really had was siding with Orpheus on the off chance the Githyanki civil war would kill enough of them to keep them from consolidating enough power to be a threat to my character on the prime.
I'm the same, I start off with the intention of being a bad guy in a RPG and end up doing all the good guy quests
As many sane evil characters would, at least when those goals are not diametrically opposed to their own and didn't involve risks that outweighed the rewards.
Being well liked and widely respected are powerful advantages worth fighting for, especially if one is a selfish monster with long term plans. Likewise, doing 'good' is not going to offend most 'evil' individuals in the slightest. Everyone wants to advance their ideal of good and most people with even vaguely similar fundamental needs and desires will view most of the same things as good. The difference is that the evil types don't respect differences of opinion and have no compunctions about doing whatever they think they can get away with to advance their goals and ideals.
From the outside, or in the short term, evil characters can often be more effective at achieving good goals. It's their methods, when they are known, that should raise eyebrows. The devil is in the details.