There may well be a lot of bad, boring, or inconsequential journalism out there designed to generate click-throughs -- the push for this is partly why I left the industry -- but you can look up the list of Pulitzer Prize winners, recent and past, if you need a reminder of why we need an independent press that acts as a public service.
Speaking truth to power is not congruent to tearing down the dominant paradigm.
If you oppose the dominant paradigm, it should be because the dominant paradigm is wrong, not because it's dominant.
What is this "check" then? SCOTUS checks legislation by throwing it out. Nobody has elected or consented to "journalists" having a constitional role. That being said, the constitution protects the people to talk amongst themselves, so that the electorate is itself effective, and can check power via the ballot box.
The issue at hand is the role of money in the "talk amongst yourselves" narrative. And its potential corrupting influence (bascially--buying vote for special interests and PR clients).