For reference, Worm is divided into 30 arcs, of roughly 50,000 words each. I divide this into a few major sections.
Arcs 1-3: Taylor (the main character) gains her superpowers, learns to use them, and joins a team. She struggles a bit with hiding her new powers from her family. This is the only part of the story I thought was any good. By the end of this section, Taylor completes her metamorphosis from awkward teenageer into standardized rationalfic protagonist, and generally stops being an interesting character.
Arcs 4-20: Taylor and her team do typical cape stuff, mostly fighting various superpowered opponents, finding allies, and building influence in their home city. This was tolerable until I realized that the author is constitutionally incapable of letting his protagonists take any kind of meaningful loss. This section is a million words long and has no substantial consequences.
Arcs 21-27: I may have gotten the exact cutoff wrong, but somewhere around arc 20, there's an event that looks like it's going to cause a major shift in the story. Unfortunately, those major changes generally fail to materialize. This section is more of the same, though a bit more tolerable due to the novelty of having a bunch of new characters running around.
Arcs 28-29: Again, I'm probably off by an arc or two, but around arc 27, there's another big event. This time, there are some big changes to the story, but they're largely for the worse. All logic goes out the window, and the consequences of the big event are almost entirely ignored, in favor of buildup for the big finale.
Arc 30: This is hands-down the worst ending I have ever read in any piece of fiction. The climactic fight scene is largely told, not shown, and the author utterly fails at conveying the intended epic scale. The worst part of all, I'll omit due to spoilers, but in short, certain details of the battle make the previous 6,000 pages look like a complete and total waste of the reader's time.
There were two reasons I stuck with Worm for the full 1,600,000 words, in spite of its main plotline being dreadfully repetitive and boring. First, the interlude chapters, which explore backstories of side characters and the nature of superpowers, I thought were generally decent. And second, I was expecting all of Taylor's team's politicking and base-building to pay off eventually. (I had previously read Austraeoh, where I slogged through the million words of books 2-4, and it was worth it due to the excellent book 6.) But I was utterly wrong on the second point, and the first alone is not sufficient to make Worm worth reading.