A free press is literally what it says on the tin - they can publish what they like. The benefits are the wealthy and powerful being held to account. The negatives are sometimes they will overstep the line and get it wrong.
Governments and the wealthy will use their resources to try and control their image: they will sue on the most minor points of law (like copyright infringement!), they will brief the press, they will set up events likely to show them in a good light, they might even have a favoured reporter, they might try to skip the press and publish their version of events directly to the public, but… because we have a free press, the press don’t just talk to them.
By symbiotic - you mean, not really, more parasitic since the media always kill the host. I don’t even mean that in a bad way! That’s the media doing its job.
They may have an editorial stance but a) often it will surprise you, and b) that doesn’t stop news being reported. It was The Mail that relentlessly campaigned for justice for Stephen Lawrence (they called the killers “murderers” on the front page and challenged them to sue) and was ultimately successful, it was The Telegraph that exposed the expenses scandal that brought down quite a few MPs, etc.
The reason you know that Kate looked nice at Wimbledon is because it was published in the papers. The reason you know Kate’s brother-in-law is a bit dodgy (and so is her sister’s father-in-law), her brother keeps failing businesses, her parents’ company had to take out a covid loan and then collapsed once it was sold, her tour to the Bahamas didn’t go well, she had fallen out with Meghan… the only reason you know all that is because it was printed by the same papers.
Almost every single negative story that you know about the rich and powerful, you know because it was printed by the free press. Every law that you can pass to gag the press about an ex-royal will be used to gag the press about a government minister.
And writing a column is not really journalism, it’s offering a view. Boris Johnson was a columnist long before he was a politician. Columnists are not breaking stories about the Sussexes, don’t worry.