so why did danny become a superhero anyway?
because he very clearly does not want to be one. there's multiple plot lines about him wishing he could get rid of his powers and live a normal life. he's constantly talking about wanting to have "a weekend free of ghosts!" "a camping trip free of ghosts!" etc etc. he seems pretty desperate to get away from it all. so it clearly doesn't give him a sense of purpose or anything. its like a chore to him.
in s3 we see that he doesn't even like the positive attention he gets from being a hero with him trying to avoid his fans. he doesn't take any enjoyment out of dash being excited to be around him when he's phantom. he used to like that paulina liked him, but pretty soon that became something that annoyed him as well.
he doesnt even like superheros. according to tucker in season 2 danny doesn't read a lot of comics, or at least not superhero comics, and the one we see dani reading in s2 looks more scifi than superhero.
he doesn't have any real drive or motivation for being a hero. no dead relative no moral code passed down from a mentor, literally nothing. he just is one. its like a fact of life.
so ive come up with a couple answers that i like.
Danny has a very strong sense of responsibility. This is probably the most canon accurate answer. If something bad happens to someone, and he feels like he has the ability to have prevented that disaster, he's going to blame himself for that disaster. We see this with Cujo causing Valerie's dad to lose his job. We also see it in the Spectra episode where Danny beats himself up for literally every mistake he makes.
The interesting thing to me about Danny's strong sense of responsibility is that he's not really that nice of a guy. He can be really rude and dismissive even to the people he loves. And he doesn't seem super hung up on the morals of what he does. He has no problem overshadowing people, or using his powers for personal gain, or using them to humiliate Dash. Like he really doesn't have much of a moral compass beyond "I don't want people to die."
But "I don't want people do die" pretty quickly spirals into "I need to be a non stop vigilante" when you have ghost powers and think that the bad actions of others are your fault if there was even a slim chance you could've stopped them and didn't try.
Danny consistently tries to do what is morally right the way that a tired teenager begrudgingly takes their dog on a walk. Life would be so much easier if he just left things alone. The town would probably be fine if he let things go for a day or two, we know that he thinks this as well because he's constantly saying stuff like "I don't want to care about ghost fighting this weekend." Surely he wouldn't even think about taking a break from his regular ghost fighting if he didn't think Amity Park could survive a couple days on it's own. But then the dog is looking at you and it looks so sad and restless and it would be so much happier if you took it on a walk. And you're tired and just want to scroll on your phone but you're not really doing anything this afternoon and it'll take like 30 minutes before the dog is tired out so you just do it anyway. That's kinda Danny with his ghost powers in my opinion. If that makes any sense.
In large part I feel like Sam and Tucker probably just told him to start fighting ghosts and he did. Hear me out on this but it's my personal head canon as to why he took up ghost fighting in the first place. While Danny doesn't have much of a desire to be a hero, Sam and Tucker totally do.
Tucker loves superheros. Sam has strong morals. Both of them love things that are unusual and don't want their life to be boring.
And Danny is usually pretty agreeable with whatever they want him to do. He really value's their opinion, even if sometimes he can be oblivious to how he's ignoring them/hurting their feelings. There's a ton of scenes in the show where, when faced with a moral dilemma, Sam and Tucker both have a strong opinion on what Danny should do and he just agrees with one of them.
So I very much see a scenario where Danny, Sam, and Tucker have been learning about Danny's powers for a couple weeks, a ghost attack happens, and the two of them tell him to do something about it. So he does something about it. Because they're his friends.
Danny can be kind of a passive protagonist sometimes which is another thing I find really interesting about him. His opinion is pretty easily swayed by the people around him. And it's shown as both a flaw and and a positive thing which is also really interesting to me. Because he can be swayed to do something bad but he can also be swayed to do something good. It's a cool trait to give a teenage character because obviously teenagers really care about their peers opinions of them. And we know that Danny really doesn't want to be seen as a loser, which is another thing that points to him kinda just going along with popular opinion. So basically I think Danny became a superhero because of peer pressure.
And okay. This is my super crazy one based on the weird crazy Danny I have in my head. So this is basically all head canon take it or leave it. But Danny is like. Super obsessed with normalcy. It's the biggest difference between him and SamAndTucker. Sam loves to be unusual and go against the grain. While Tucker doesn't really like being seen as weird, being a technogeek is a huge part of his identity. But Danny consistently is described as exceptionally average by the people around him. Literally all he wants is for things to be normal. It's why he doesn't want to fight ghosts. It's why he doesn't want ghost powers. It's why he gets upset at his parents sometimes.
I mean it makes perfect sense. His life is pretty crazy. He was alienated from his classmates before he even got a chance to take a swing at the social ladder because his parents are crazy ghost hunters. He grew up surrounded by ecto weapons and crazy experiments and a lab underneath his house. When you look at Danny, his interests and opinions and personality, he's really just an average guy. The only reason he's a social outcast is because weirdness just kind of clings to him, not because he himself is weird.
And he'd really just like to maintain the status quo if at all possible.
So what is normal when you die and become half ghost? Suddenly you're a teenager with superpowers. There's no real script you can follow when that happens. Except there is. Because even if no one like that exists in real life, there's plenty of examples of what a teenager who got caught in a horrible lab accident and ended up with superpowers should do.
Even if Danny isn't a big fan of superheros, surely he can still use superhero backstories as a reference for what he's supposed to do here. He isn't thinking about what he wants to do with his powers the way Vlad did. He's just thinking "Okay. What is the thing you are supposed to do in this situation?" And according to most media, the answer is Become A Superhero. And so he became a superhero.
This is why it feels so much like an inevitability that he's Phantom. Because to him it kind of is. To Danny, in my opinion, there's kind of a checklist in his mind titled How To Be A Perfectly Regular Teenage Boy. He likes video games. He likes junk food. He likes football. He likes pretty girls. And then that all kind of gets jumbled up with the introduction of superpowers. So now he has a new checklist in his head called How To Be A Perfectly Regular Teenage Boy With Superpowers. He saves people. He uses his powers to fight bad guys. He does the right thing. That's what you're supposed to do when something like this happens to you so that's what he does.
Thanks for reading all of this I really don't know how to end it. But I love Danny Fenton. I love him so much. This guy is just so strange. What is up with him.