You can watch snapchat stories from the NYTimes, The Economist, WSJ, in addition to a whole bunch of other sophisticated serious media organizations. Often times the articles they publish on their stories, are just more interactive versions of the articles they published on their website with the text being the same.
The thing is, tabloids are just more popular than sophisticated news. People are more interested in buzzfeed or mashable or people magazine than they are with politics.
We can try to argue about the definition of "substantial" if you want, but in the end, the fact is that I can find you ten thousand young teens that don't give a fuck about politics and do give many fucks about a Kardashian booty transplant.
I think its pretty clear and universal what "news of substance" means in the context of news journalism. In fact most newspapers have a separate section for entertainment for this reason.
Your comment and diction seem be the very definition of "insubstantial."