I agree. This is a growing problem, in my opinion. One of the biggest advantages (and most important roles) of traditional media is that you're getting a wide variety of information about different topics.
More and more over the past 10 years or so, apps/sites are either choosing for you what they think you want to read, pushing what they want you to read, or letting you personalize things so much that you could become completely shut off from new things that might be interesting or important for you to read.
I'm not just talking about the headlines of current events that people should generally be aware of to be informed about what's going on in the world, but also feature stories about subjects you may never have even heard of before and wouldn't show up as something you like based on previous reading data, but which you might find interesting/funny/cool if you saw the headline or the photo for it.
Sure, the answer to this is to go buy a newspaper or or an online subscriptions to one. But these cost money (and they should) and people are getting more and more used to the idea of things being free or free with ads.
Apple News and similar programs have a lot more potential because they draw from so many more sources. Part of it will depend on what sources you tell Apple News to draw from and what you end up reading. But over time, based on the description at least, if you just read what is put front and center to you in the app, you will be exposed even less to a wide variety of news and more to the narrow range of stories the app deems to be related to your previous reading patterns.