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.
This has more or less always been the case.