Very briefly you are not wrong, yellow journalism has a long history is not new. In America from the times of federalist papers through slavery and jim crow and antisemitism of the 30s, to civil rights and into modern times it has been a powerful tool to shape public opinion.
There is nuance to this however, the era of professional journalism has been brief, only 100 or so years. In that time, media had the most impact in shinning the light on the truth, notably with reporting on Watergate, Pentagon papers or Hershey on Hiroshima and so on, that era is coming to an end.
As the cost of publishing drops orders of magnitude in every generation of technology as it happened with cheap and fast printing press, radio, broadcast and then cable TV and finally the internet and mobile, the problem becomes more massive and much harder to regulate, and also drops in the quality of public discourse and nature of truth.
Basically it boils down to we had a good(relatively) 100 year run with media and corresponding improvement in civil liberties and good governance, we can no longer depend on educated public taking decisions sooner or later in the right direction like we have last century or so.