Pith is a fantasy coming-of-age story with succintly-portrayed but uniquely compelling worldbuilding that dips into some cyberpunk themes with its use of souls as a setting conceit ala Pillars of Eternity, but while that stuff is great, it's not what truly sets it apart from other web fic - you can find piles of stuff with charming characters and interesting worlds that, unfortunately, don't really know what to do with them. No, what makes Pith almost unique and especially worth your time is the technical skill with which it is written.
Even among the more professional stuff like PGTE and Wildbow's work, I have never seen a serial webnovel with such a clear and consistent idea of exactly what it's trying to do, both thematically and on the micro and macro levels of the narrative, and with such calculated pacing to execute on those aims. The story is fast; most chapters get through multiple scenes and plot beats, while staying consistently within the 4-8k word range. The story is dense; it's rare that you'll leave a chapter without the sense of having learned something important.
But what's most impressive is the deftness with which the differents characters and plot elements are woven together. Though there are two protagonists who gets the lions share of the screen time, there are piles of important recurring characters, very few of whom spend much time together in the kind of RPG party-style situation you tend to expect in these works. Yet they're all interconnected in complex and often surprising ways that emerge over the course of the narrative, both directly and in how they thematically mirror and contrast each other. Characters you initially dismiss as auxiliary end up linking back to and reinforcing the main story, goals which seem individual all ultimately tie into the central conflict. It never wastes time or narrative energy on anything.
I also write webfic, and a lot of the time, when I'm reading other works, I get envious in a silly and childish way about the success of the story, thinking stuff like, "hey, why is this so popular! I could do better than that!" or "people only like this because of its gimmick/because it's easy to read/because it's a litRPG/etc!"
Pith is the only story I've found where I instead feel envious of the sheer technical competence of the author. I wish I could put crap like this out with only a few days to write and edit. I don't know how she does it.
All of this is without even really going into the content of the story. As for that, probably the most I can say without spoilers is that it's dark and often depressing. It's extremely effective at evoking emotional responses in the reader - right at the start, the story grabs you by the throat with a painful scenario, then throws painful spanner-after-spanner in the works of it's resolution... And by the time it does get resolved, you've seen so many tragic things, been made to care about so many other people who are equal victims of the tragic complexity of the situation, that it's not even clear if it matters any more. It captures the same feel as the first half of Worm, in a lot of senses.
However, unlike Worm, there is a core of optimism and hope to Pith, a beating human-feeling heart to the characters and their desires to change the world for the better (as horribly misguided as their approach may be), that gives it a fundamentally different feeling. Most people I've heard of dropping the story I've heard of have done so because it's depressing. I did, too, when I first started.
To those people, I would say to try and stick it out. Pith is a story about systems of control and oppression, loss of identity both literal and otherwise, and how difficult it is to hold on to the things important to you in the face of the unspeakable cruelty and apathy of both others and the cosmos itself. But it is also one that vindicates holding on to idealism, to not losing yourself even in the face of ugly and imperfect reality. And ultimately, is a story about how friendship and genuine love can save even the most awful people, even if just a little bit. And we're only at the end of the first book.
This story is different from a lot of LitRPGs in that the progression element, which is usually front and center, is more of a device to explore the setting and drive the characters rather than the subject of focus in of itself - though that isn't to say it's not satisfying for people who enjoy that sort of thing, but rather that the elements are married in a way that many of these kinds of stories fail to manage. It's good stuff.
As written so far, the content of the story is mostly the sort slow-paced but action heavy dungeon crawling you'd see in most stories of this type, but with a lot more flavour. Most of the narrative attention goes to the developing friendship/possible romance between the two leads, both of which are interesting characters that don't fall cleanly into any standard archetypes. The dialogue is punchy and often cute, and the character exposition well integrated and paced, though occasionally it can feel somewhat overwhelming.
As for the setting, while it's fairly standard fantasy on the surface, there's an undertone of grotesque imagery and horror that makes it unique without going over the top into grimdark territory. Overall, a great start.