Nostalgia aside, I think generally speaking, there are two ends of the spectrum called "kids' shows".
First, the one that's either "dumbed down" or very age-specific in themes, which makes adults go "I know that already, ugh" or "wow, silly kiddy problems", but younger children especially gobble up like candy. They're extremely moralizing, slower paced, and not very subtle, in order to make it understandable for even the youngest audiences.
Second, the type that is suitable for kids mainly because of the absence of anything adult-specific, such as gore or sex, but retains everything else that's in "good grown-up stories", such as story arcs, complex characters, or even deeper conflicts. This is more universal in age.
I like(d) watching Voltron, Avatar TLAB, Danny Phantom, Miraculous Ladybug and Mysterious Joker, for example, which I'd place nearer the second category, and I'm pretty sure none of them actively target an "older" audience. Reasons are different for everyone, but for me the appeal is in getting well-written characters, smart dialogue, a general story to follow and pure, unbridled fun not bogged down by unnecessary sex and violence. I groan when hollywood movies throw in the mandatory sex scene that's just slowing the story down. I sigh when boobs bounce across the scene. I zone out when a show is only about maximum slaughter. It feels cheap, old, and overused to me. Kid's shows can be refreshing in their "back to basics" approach to simply having an enjoyable story. Not to say that there's no trash out there but yah.
Then there's this internal block that many adults have along the lines of something being wrong with watching kids' shows? There isn't really, and if it's fun there's no reason an adult can't enjoy it. That it's not bloody or sexy doesn't invalidate it. Honestly I was a bit on the edge about mysterious joker/kaitou joker, because the opening felt very "kiddy" at first, but boy am I glad I stuck with it. I sing along every time now and that show is just plain fun!
Also, this:
Noot noot!
Edit: How do I end up writing long-ass analytical posts every single time.