I grew up preferring the styles of Nick and Disney over CN. The only stuff I watched on there was really their classic Tom & Jerry and Hanna-Barbera stuff. I'm kind of ashamed to say I'm not really a big fan of the stuff on there that's really popular today, mainly because I'm more of a traditionalist and not a fan of the art and writing styles, especially with some of the shows being very similar to each other in those respects. I'm talking about Steven Universe, Adventure Time, Regular Show, Clarence, and We Bare Bears mainly. I've seen two episodes of Steven, two of Adventure Time, and about four or five of We Bare Bears and I'll give it that they're decent, respectable shows deserving of their fanbases. They're just not the kind of shows I'd see myself following week after week as a matter of personal tastes and preferences.
The Amazing World of Gumball is really my favorite show on there. I admire the surreal takes on some stock sitcom tropes, the cultural awareness of its humor, and that the next episode as of the time of this post is going to be ripping on their notorious Chinese knockoff (Miracle Star), which is so accurate that the parody looks just like the actual knockoff and hawks the exact same kind of product. Its humor has the same kind of edginess to it that Gravity Falls had - relying mainly on the banter between its main characters, their reactions to the strange occurrences around them, and making jokes about pop culture, history, science, and like subjects that probably not even Animaniacs would have thought of, even if it was still around today. The only thing I wish it would have done better is to make its supporting cast more interesting. Outside of Gumball, Darwin, and Nicole, I can't really enjoy any of the other characters all that much and I hate Richard with the passion of a Tsar Bomba.
I can't comment from a particularly strong standpoint about Teen Titans Go or the new Powerpuff Girls, but I think the way TTG's creators address the criticisms from the fanbase is horrible and could be done a lot better. I have seen a couple of episodes of the new Powerpuff Girls and it seems to be written like such an average, nondescript, and uninspiring show that uses its franchise as a crutch, something which I really can't stand given the dominance established franchises have over the medium these days. It's not anything new to CN; I label The Looney Tunes Show and Sonic Boom guilty of the same and yet a majority of people actually like those shows.
I have seen some episodes of Magiswords and I find it enjoyable in small doses. I've followed the show's creator on DeviantArt since shortly before the show was picked up and he's a respectably talented artist.
As far as action cartoons go, it's mainly an issue of economics more than any decisions Cartoon Network is making. Original action cartoons have pretty much been on life support ever since Nick fumbled Korra and the creators of the Avatar franchise left TV in favor of digital comics. Only Disney seems particularly interested in cranking out shows based on the same 5 Marvel superheroes and Star Wars stories on a regular basis now. The reason is because action cartoons typically have higher budgets than comedy cartoons due to their more complex character and prop designs and higher standard of effects animation. As a result, action cartoons are more heavily reliant on merchandising and advertising to make back their dollar. But, wouldn't you know it, toy sales and advertiser interest are both going down at the same time, ratings are going down due to audience fragmentation and competition with other forms of entertainment, and licensing and endorsement deals are much harder to come by today for newer franchises than legacy ones from the Saturday Morning era. Although interest from teen and young adult audiences seems to be at an all-time high, this is still a very fickle niche audience contingent too small to justify any high level of investment. No one knows how to really deal with it.
As far as Cartoon Network's future goes, all I can say is that it doesn't look good if it's mainly in nostalgia revivals. However, the same experimental writing and art styles that started with AT and SU seem to be continuing with future original projects, so it may look good if you're a fan of those kinds of shows. Steven Universe does still seem to have quite a bit of life left in it considering it's still successful and in its fourth season.