I mean, HN, Reddit and what other social sites do the same thing, and you could still go where you want without relying on internet“channels” or google searches, but most people don’t.
Good point, I would say however that you create/add the sources first (by following), Facebook then guides what you see, based on your behavior.
Facebook doesn't decide upon, and broadcast a pre-determined message - they simply work off of your preferences, and try to give you more of what you want (not need) with a healthy side of advertising.
Echo chambers are a dangerous thing that people should be educated about early and often.