How normals are depicted often matters in superhero works because they portray how much you can get done, and how much you can *matter* in this world if you haven't been gifted powers. Can you use sheer grit or emotional connection to become a real player, or do external factors dominate over human will? Are you a joke, or are you a badass normal?
Normals after all usually get pigeon holed into one of those two groups. A person without any powers who through cleverness and stubbornness makes the godlike characters have to contend with them, is a badass normal. In other stories, a character who tries that may be doomed to patheticness for their hubris, or become evil with their obsession (such as in The Incredibles.)
Let's go over these often overlooked characters.
(It should be noted that by making the Tinker power a literal power, many character types who would be "badass normals" in other franchises - such as Iron Man or Batman - are parahumans in Worm. This is a respectable choice, because "the money and intelligence to invent a flying suit of power armor" is as out of the realm of possibility for most people as being born on Krypton being shot with gamma rays.)
Danny Hebert - Joke(ish). Oh Danny. The narrative doesn't clown on him, and he loves his daughter so much, but he is pretty ineffectual at anything regarding her. He doesn't understand her bullying, he doesn't cotton on to her powers, and he tries to cut her off from her new life with very little success. It's very hard for him to compare with her new connections like Tattletale and Grue, which puts the normal/parahuman disconnect in the age old theme of parent/teenager disconnect. Sad but well done.
Emma - Joke. The first antagonist, Taylor's ex-best-friend betrays her partly for a cooler friend, but more for finding a way to reconstruct her personal identity after a traumatic attack (you could even say that was her "trigger" event.) Emma and Sophie's obsession with bad Nietzchien philosophy - either you are the predator or you are the prey - is depicted as stupid but seductive in the Worm universe. And for all the many victories Taylor accomplishes over her, by achieving them through might, she never really proves that their philosophy was wrong, only that she was a superior predator.
Jessica Yamada - Badass. Worm's best therapist ever, she cares deeply about her parahuman patients, taking great risks to even be in the same room with them, and offering openness and honesty to Taylor.
Kevin - Badass. We went over his role a few posts ago.
Stan the reporter - Joke. Remember him? One interlude is about a skeevy reporter trying to get the story about Taylor before any other news outlet does. It explains his perspective well, and you can understand how the demands of his job and the sort of creative ambition that any cape has, lead him down this path. But really he comes across as an example of how another power in this world - the media- can be used to bully people, coercing and manipulating people to give their story in the way the reporter wants it.
Calle - Badass. The "superhero's lawyer" is another well-worn archetype, but Calle gets a brief appearance here to show that Wildbow can write that sort of dry with and competence with systemic rules, fairly well.
Tagg - Joke. The next PRT director, he not only reiterates how bullying can be used from the position of legal power, but particularly how bullying is a vicious cycle between both parties. He explictly states how his presence and attitude are a reaction to how Taylor and crew have been mopping the floor with the PRT. After the way the Undersiders made fools of the Brockton Bay PRT, the PRT had to respond with more stubbornness, more force, and more targeted treatment. The escalation is inevitable.
Glenn Chambers - Badass. Initially a joke as much as any "PR consultant who tries to tell the superhumans how to act and dress" would come off as, more obsessed with appearance than substantive matters. But Worm then treats him very seriously, with Taylor observing how his form social power is almost as alien and weird as any parahuman. He then is one of the few people who ever breaks through Taylor's stubbornness, talking about the real importance of costumes, self-imposed limitations, how parahumans use their powers, and trust. This centers on showing Taylor footage of one of her attacks, and how she looks like a creepy serial killer. Taylor focuses on the distance between her interiority and this appearance, but Chambers only sees why the appearance is a problem.
Saint - Joke. Like Saint George and the Dragon? He is probably the most clowned on character in Worm, while the seed of his plot is a fairly common scifi type. Geek finds the codes that are the only thing that can defy the superpowerful-AI, and tries to use them to contain this epic threat. And instead he comes off as a bumbling doofus who has not earned that power and is only hurting someone we both care about and who is very necessary for doing good. He is so annoying that it might take a while before you realize you are rooting for the unstoppable AI to throw off any shackles inhibiting it.
That PRT guy who caught Jack - Remember him? Golem realized Jack had a secondary power that let him predict parahumans (or something), and so the only way to take him down was "a normal with a gun." What's notable is that Golem didn't use any established normal that we know for this. It ended up being someone completely anonymous whose name I don't even think we get. This gives the scene the meta-literary feel that it was *characters* who Jack's power worked on, and Golem needed a non-character to take him down.
And I don't think any new normals do something useful or get serious characterization after that, through the rest of the story, until we meet Taylor's AU mother at the very end.
Reviewing this list reminds me how some of my favorite characters are normals (Yamada, Chambers, Kevin). But then Worm's characters are so compelling that I end up saying that about most random selections of people in the story.
(There's also an excellent Interlude from the perspective of the dog Brutus, but that's more about insight into Bitch. Still, respect for the way Worm tries to humanize animals.)
Add some other normals in the comments who you think are relevant that I've forgotten.