Frankly I think this has always been true. The internet however acts as an accelerant and broadens the spectrum of extremes, as it does with most things.
People have always had a choice as to where they get their news and whether or not they believe it, or how much of it to believe. People have always been influenced by what their peers read; that’s why papers have clear demographics for advertisers to target.
The truth is not absolute, as your graph illustrates, it’s often also quite boring and complex. Most purveyors of bullshit do so in a short, sharp and direct manner which is much easier to digest and regurgitate.
The answer is probably the same as it’s always been – critical thinking. Who’s written/published what I’ve just read? What are their motives? What are their political alliances? What vested interests do they have? How might any and all of that have coloured what they’ve written?
I think dissecting such questions could be codified to a pretty decent level in time, such that you could indicate the likely independence/accuracy of an article.
I do wonder to what degree using or highlighting this indication would make a difference however. I think a lot of people who read bullshit kinda know it’s pretty high on the bullshit graph, but like it none the less.