The link doesn’t work for me, but based off your comment: I can accept that mainstream journalism is generally in decline in various ways. But it is curious they chose to single out WSJ, which is considered more balanced and less biased than NYT or whoever else (https://www.allsides.com/media-bias/media-bias-chart). Or is it just to point out that even WSJ is subject to this issue?
When framed in terms of bias, the implication is that things in the centre are unbiased, or that the bias somehow equals out — that you get the best picture by reading those news sources.
...when the truth is that no news source is unbiased. Period.
Even if a particular source somehow manages to perfectly balance between whatever the current "left" and "right" are in that political environment, that doesn't make it free of bias. Sometimes the people on one side of the political spectrum in a given environment are genuinely, collectively, doing bad things! Sometimes there are personal biases! Sometimes the political environment shifts, and leaves you behind!
In general, it's much more important and productive to be aware of and transparent about your own biases than it is to try to present yourself as "unbiased".
You say that the WSJ is "more balanced and less biased than NYT", based on that website.
But a bias towards centrist American politics doesn't mean a lack of bias — far from it.
For example, 30 years ago a "centrist" report on global warming might have given equal space to right-wing and liberal perspectives, even though the vast majority of scientists at the time sided with liberals on the facts.
20-ish years ago a centrist report on Iraq would have parroted the administration's lies about WMDs and the urgency of going to war. And the New York Times was one of those organisations!
Presumably because WSJ is the one who wrote the article this person found objectionable. NYT did not write such an article.
They did say "The epistemic collapse is total when traditional high-quality information sources like the Wall Street Journal", so there is probably an element of attacking what is high quality though. [I dont follow us media landscape, i have no idea what the relative quality of various papers are or if you are correct about NYT]
That said, more generally when constructing arguments, you generally want to attack the strongest version of your opponents argument. Attacking a paper known for being higher quality is always going to be more convincing than attacking a paper that is less known.
It's addressing an article published by the Wall Street Journal. It's not singling it out as a uniquely bad publication or saying any other popular publication is doing better.
The total count of e.g. newspaper owners, and especially radio and TV owners (because there used to be laws against that being too concentrated, for one thing), has plummeted, though. Lots and lots of consolidation, lots of small outlets surviving only as barely-staffed zombies under big owners.
Pressure due to the Internet killing their business models (see the last season of The Wire for a view of what this looked like when it was getting into full swing and the old serious-journalism newsrooms were rapidly being destroyed by cost-cutting and chasing dwindling numbers of eyeballs, even if the outlet survived in some form) plus changes to laws, including the ones referenced above but also a drastic weakening of anti-trust enforcement in the '70s, have made things very different for our news media than they were from the end of WWII through roughly the '90s.