I posted about this in another thread, as adult you don't get into as much stuff because it doesn't have the wonder it did as a kid, sure it happens from time to time with a franchise but it's rare. It doesn't help that we mostly get reboots rather than new ideas most of the time so there's even less content to go for.
There's still a few things I'd like to see perhaps new versions of or whatever but at this point I don't care about any new superhero cartoon or movies, sure I'll watch them but I can't get excited for Batman Movie 13 knahen I got into Batman Begins in my teens or Forever/&Robin as a kid. Same with TMNT, we've seen so many stories it's hard to get too excited even if I love TMNT. But I'd welcome a new version of Freakazoid for example since it hasn't been rebooted to death but I'd rather have a new show but none have really made me get super excited, I liked
Kipo and
Glitch Techs but not the same as say if I had been a kid.
I'm fine with this as well since as an adult I have other responsibilities and other hobbies which take my time so I don't have time to watch stuff anyway. I'm not all jaded either, if something was surprising enough I'd get hyped up like a little kid again.
Edit:
To add to this I learned from Star Wars and Pokemon that new versions don't ruin what you love, I can still love the version that I liked, I'll always have the things that I love and there's plenty of content from that era for me to enjoy like 90s Star Wars books and whatnot so I can geek out on just that version. A new version won't ruin my childhood, especially if it's a reboot unrelated to it. It hurts more when it was like the sequel trilogy but whatever, I can ignore it, there's more SWs content than I'll ever be able to consume from the era that I do love. Sometimes things just aren't for you anymore. Many hated Episode 1, I was a kid so I loved it, I don't care people who weren't the right age didn't enjoy it, I loved Godzilla 1998 and I feel no shame and I won't call him "Zilla". If I rage over new stuff it's the same exact thing. The SWs sequels suck, who cares, I won't argue with those who like them, I'll just avoid that.