All of that comes down to the main quest and central themes/problems the game revolves around, which is that there are no answers to the great questions in life because it seems life is meaningless, so much to the point that people created a pantheon of gods to try to fill in the aching existential wound.
It's not like there isn't a similar/exact same school of thought in real life, while people still exist and haven't committed mass suicide. However, nihilism isn't the theme of PoE, PoE doesn't have a theme because it doesn't have a plot, let alone a coherent one which underlines a philosophical understanding of life. That sounds comical in the context of PoE. Whatever Thaos fantasizes and illudes about in his mind is his problem, not to mention that he doesn't think life is meaningless, at least not his own. He thinks his purpose is to keep some "great secret" at all cost. I've heard some people say that "unanswered questions" are the theme of PoE, but I've argued that the only unanswered question is Eder's and arguably Kana's. Even if, somehow, people manage to find more, the theme can't be unanswered questions because the ramifications of such aren't explored, they just shrug and go "oh, well, better luck next time". Maybe, at the most, with a lot of creativity and hyperinterpretation, you can say that "the search for answers" is a main goal for a lot of the people in the story.
Which is exactly what Josh tries to do with removing xp for combat.
There is xp for combat, it's just called "filling the bestiary".
To join in the other discussion about knight-errants - I don't think it matters whether adventuring is realistic or not, it obviously isn't. It's a fabrication concocted by troubadours and poets, much like the modern conception of "soul mates" and "romantic love". There is no realistic, sane person who goes around helping random people with their troubles, that's why Don Quixote was written, to show the absurdity of such a situation. RPGs, however, can get away with this because of the xp system and the desire for non-linearity. Yes, some examples are better than others, but it very much depends on the framing of the main quest and whether it permits such going around doing random tasks. These random tasks
shouldn't be random, they should still serve some kind of purpose within the whole, that's why art exists as a rationalized
construct, to not be random. Otherwise you can just improvise the quests along the way (it feels like they are doing exactly this) and it wouldn't make a lick of difference, and it doesn't. Battle Brothers is a perfect example of this, the quests are literally improvised by the systems and the end goal of the characters is self-advancement and personal wealth. Is Battle Brothers narratively engaging? I wouldn't say so, people don't play it for the story.
EDIT: There's a reason poets and troubadours "romanticized" the adventuring knight seeking the love of the maiden, saving the village, whatever. Apart from it being a more honorable goal in the context of Christianity, it also provides a concrete point to the narrative, "self-advancement" is too vague to work and it requires an arbitrary stop point. The logic in art isn't exactly the one in real life, it operates on different assumptions. Art can't be, and isn't, about normality. The narrative structure (at least then) requires many different aspects to be accounted for and an end goal is one of them. Freeform and unending narratives have been done in modern literature, but games such as these employ more standard formats.
EDIT2: Here's an interesting homework exercise: What do you think is the ending to PoE? Dealing with Thaos, ending the Hollowborn Crisis or fixing your Watcher symptoms? Or, if you prefer, let's format the question this way - which of these three, if not all, end points can PoE go without?
better game.
