It's not that I hate teen superheroes. I grew up loving Spider-Man, Teen Titans, Iron Man: Armoured Adventures, etc., but now that I'm older, I'm really tired of teen superheroes, mainly because in comics characters never really age, and when they get rebooted in cartoons, movies or TV shows, they usually just start the story around their origin story or after, so whenever Spider-Man gets rebooted, he's always in high school despite him graduating high school in issue #28 and then graduating college in issue #185. So he wasn't a teenager for really that long, but at the time he got powers and became a superhero at 15 years old, and that wasn't very common back then; most teen heroes were just sidekicks. And because Spider-Man is mostly marketed to kids (at least the TV shows and movies), they make him a teenager to appeal to kids.
Despite the fact that a lot of good, the best and mature Spider-Man stories come from when he's in college or at least graduated from his first 4 years of college, even in cartoons he's only been in his early 20s for two shows: Spider-Man: The Animated Series and Spider-Man: The New Animated Series โ that's it. And Spider-Man has had at least 12 distinct animated TV series based on Spider-Man, and he's only been an adult in two of them.
Basically, I'm tired of teen superheroes because I feel like it limits the storylines you can do, and because of comic book logic, the characters never age, so any time they are rebooted, they will be a teenager because that's their starting point. It's the same with Ms Marvel; she's still a teenager despite the fact that she should be 28 years old now because she was 16 in 2013. But also it's like there's no middle ground: if you are a "young" superhero, you are a literal child, and if you are an "adult" superhero, you are in your 30s or 40s. People in their 20s do exist.
My wife's favorite anime series is My Hero Academia, which features teen superheroes. It's fine, but the fandom can be a bit... extra. Like the mangaka (author/artist) did not do relationships because they're focused on heroics and because they're kids. He actually got death threats because the main guy and the main girl didn't get together at the end. So he released a chapter that so far has only been released in Japan legally, where they're showing holding hands at the end. And it's more of a "team up" gesture than a romantic one. Still, it tipped off a wave of homophobia among some fans as some people had shipped the main guy with other male heroes, and the main girl with the villain girl. They believed that the mangaka had endorsed their bigotry.
It's a fucking mess. But you know what it looks like? Teen drama.
Meanwhile... mine's Bungo Stray Dogs. Same concept, only the heroes are older. Okay, tiger boy is like 17? And one girl is 14-15? But the rest of them are adults. They're in their 20s and some are older. The coolest thing? Their superhero names are the names of famous writers. Their super powers are named after that writer's famous work. Like the main guy goes by Osamu Dazai (we don't know his real name) and his power is called No Longer Human. That's a real Japanese author and his most famous book. None of them are named after anyone most Westerners commonly read. There's no Stephen King, no James Patterson. That's kind of the point, these guys are more anonymous, and less flashy. They aren't even super heroes, they're detectives, and the villains are just the Mafia (they're called the Port Mafia but I guess they're supposed to be Yakuza?) and other criminal organisations. Same good superhero fun, but none of the teen drama. Not as popular over here, but apparently it's real big in Japan? I dunno. It's good shit though.
As for Peter Parker/Spider-Man, I always thought the point was he was mature for his age but still a kid.