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 – 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.
Consider more mature / adult oriented series, and literature. Marvel and DC will always appeal to the status quo.
Try Image comics. Spawn started adult and things go on from there. Tons of shit goes down including the end and rebirth of the world. Savage Dragon has run on so long that characters who weren’t even born when the series started are grown adults with kids, and the main character is literally dead (not comic book dead, just dead and gone).
In books there’s stuff like Soon I Will Be Invincible by Austin Grossman, Murs Lafferty’s Playing For Keeps, Paul Tobin’s Prepare to Die! (a somewhat vulgar example at times but also hilarious, the hero’s power is to take a year off someone’s life by punching them. Most villains just surrender when he shows up, and rarely want to fight him twice).
Also good is Marion G. Harmon’s Wearing the Cape series, wherein time passes, crazy shit goes down, heroes get hurt, die, retire, etc. Starts with the main character at 17 I think, but as of the current book she’s well into her 20s and married. This one is a mix of junior and adult capes, where superheroes are state and government sponsored as a legal requirement.