Unfortunately yup.
BG3's idea of an evil playthrough equals to all worthy NPCs dying and the player having no content to play with while losing out on all the unique items and experience by doing so. It is simply not an evil playthrough at all, instead it is a
punishment playthrough for not following the story as intended because any deviation from being a hero is just ensuring that the player has no content in future acts.
Not to mention that the player has to do some incredibly extreme mental gymnastics to barely justify committing any sort of action that goes against the obvious hero decisions, because the game does absolutely nothing to provide actual solid reasons, opportunities and content to explore them. And to make matters worse it actively keeps pushing the player towards hero actions wherever it can, such as dumping 3 tons of exposition any time an evil decision is at hand.
For example;
- Side with Minthara = Congratulations, after 3 tons of exposition you just ensured your ACT 2 is empty as hell and Last Light Inn has zero content for you, not to mention all the unique items you lost from Dammon, Mattis, Alfira etc...
- Side with Marcus = Congratulations, after 3 tons of exposition you had no content to begin with either way so you must really hate even this 0,01% of content we have for you in ACT 2
Where is Nere? Where is Marcus? Where are the Duergar? Oh right, bad guys get magically killed off-screen. Do I at least gain some unique content? Nope, because all the content is tied to the corpses I left behind in ACT 1. Not even the gnolls I rescued in Moonrise as Durge stick around to fight for me, they just magically vanish.
When I look at
evil playthroughs, I look at Star Wars KOTOR games. There evil playthroughs are so well done and immersive because you can be the most sadistically evil Sith Lord that ever lived and experience an equal amount of content throughout the entire game by doing so. You gain some unique stuff along the way as well, but you're not losing out on content. Hell, even the Jedi Knight games did the same.
I am currently almost at the end of my Honour playthrough in which I sided with Minthara, Nere and Marcus. I cut Karlach's head off and sacrificed Wyll to the Kuo-toa because he was gonna leave anyway.
Well... I had no intricate content in ACT 2 whatsoever and now in ACT 3 there's not a single reference to any of my evil actions in previous acts, IN FACT the only reference is the Steelwatch calling me out for killing Absolutists in Grymforge and Moonrise. Ain't that hilarious, once again the game punishing me for not following the hero arc 
