Spark ending opinions

I'm not a veteran of the game but I know that stalkers generally prefer less "authoritarian" factions like the Sparks, instead of authoritarian and paramilitary ones like the Wards. So I decided to side with the Sparks, (even though I had understood more or less halfway through the adventure that Scar was an idiot who lacks the lobe of his brain that allows him to reason, also considering that a moment before the end he was intent on changing his mind).

Anyway, this ending seemed a bit controversial to me, let me explain: the search for this "immortality" in another reality that ends with an illusion of this field in which apparently there are stalkers, including Richter and Scar who are grateful to you for having "saved" them and then ends with the vision of the true reality, where instead death reigns, where we see Scar kneeling near a ruined house.

I have a lot of questions about this ending, it seemed to me like the "bad ending".

What do you guys think?