At the risk of making a tu quoque argument - if you want to see unhealthy children television, look no further than Cartoon Network.
Even stuff towards the more rubbish end of the spectrum, like Teen Titans Go, obviously has really good writers and is a lot of fun, at least for somewhat older kids and their parents.
Several of its shows seem aimed at all-ages audiences, some are exclusively adult--so much so that they call the block Adult Swim--and only a few are primarily for kids.
Of those that do seem to be kids' shows, it seems to me that they are better than the cartoons I watched as a child. At the very least, they don't seem to be long-form toy advertisements.
What makes television unhealthy, anyway? Is watching Cubs baseball unhealthy? Doesn't that teach the lesson that no matter how great you look at your regular job, you will always collapse into disappointment in the postseason? Is watching Good Morning America unhealthy? Doesn't that horribly skew one's perceptions of what is actually important in life, and prime you for receptivity to advertisement? Is watching unscripted "reality" television unhealthy? ...Yes. Absolutely, it is.
> Steven Universe
This show works incredibly well. Especially since the episodes are short - a feature for parents as well as kids. Gravity Falls, as well, does a great job of being fun without trying to do much preaching. Of course, some of the adult fandom for these can be a bit ... enthusiastic, so I worry about whether the kids will be able to enjoy themselves at conventions and on the internet without getting caught up in the drama.
Both of these shows have also garnered approval from some parents with some pretty insane control issues, too. In situations like that, it's nice to be able to provide gateway entertainment to kids languishing under extreme supervision. I doubt I'm the only one who's had to deal with that. It's surprising how many parents unwittingly rob their kids of a childhood. Being a non-parent in some ways gives a more even perspective about loosening the grip on the kids and not taking everything so seriously.
Shows like Regular Show and Adventure Time are pretty good, but some parents reject them for being "too stupid". Yeah, there's juvenile behavior, but it's not all over. When introducing parents to these, I sometimes have to be particular about which episodes I start with, or they'll immediately reject it.
I've introduced teens to shows like Rick and Morty and Star vs. the Forces of Evil. Parents are generally more accepting of more edgy material at that age. And they're gonna push boundaries, so at least point them to the better quality shows. Anime has also gotten hugely popular in this recent generation, to the point that some of my nieces and nephews seem to literally breathe it. Streaming subscriptions help with that, though available shows vary by licensing deals and region. Hulu is one of the best for cartoons.
It's also amusing that the creators of these shows are the recent adults who grew up on the last generation of entertainment cartoons.