Journalism is ultimately writing about what you see and investigating it to get the facts. Most stories are broken by just one journalist, big ones sometimes multiple. Journalists don't earn very much either. This isn't an expensive endeavour compared to many things even quite small companies routinely do, like build and run a TV advertising campaign.
Moreover a lot of hard-hitting journalism appears to run on a shoestring. Look at Project Veritas. It's breaking a series of scoops about the internal behaviour of Valley firms, and it seems to basically be one or two people plus some cameras and a website.
Breaking a good, big story takes time and time takes money. Journalists don't earn a ton, but great journalists do pretty well. Their work and the merit of their work is considered worth paying for. The money has to come from somewhere.
The best a good news organization can do is not allow the money to directly influence the journalism. At least in theory then the source of the money - within reason - is somewhat irrelevant. Historically, that's advertising or subscription. People got so used to free or nearly-free journalism in the late 1800s that even today people bristle at subscription, particularly for a non-physical product. So you have advertising.
I've indeed not claimed journalism takes no money. I'm just pointing out it's not expensive. Corporations nobody has heard of routinely piss away more money than is spent on breaking a major news story by large papers on vanity website redesigns. News is extremely cheap, especially these days - so cheap it's literally given away for free.
This is fundamentally wrong. It's subsidized (largely by advertising), not naturally cheap. It's like looking at Google and saying "man, software development must be cheap, they're giving away this search engine!"
Good reporting is time and labor-intensive. It also has an extremely short shelf life, meaning the time available to extract value is limited. A single news story is financially valuable for a very short period of time.
Again, compare the cost of a news story vs many other things. Advertising campaigns are also time and labour intensive and usually only provide value for a short space of time. Yet people who do advertising work often earn more than journalists. News is simply not labour intensive, especially given that the vast majority of stories are not investigative and require nearly no effort to put together. Plus, the labour isn't well paid.
You haven't supported your argument all that well. First of all, ads have a significantly longer shelf-life than news stories and can often be re-used. Even short-term ads have value for weeks.
Second, creating a single, non-"investigative" (this is a nebulous term in this context) story takes, typically, 20-40 man hours to create and has value for typically 24 hours. 40 hours is in itself relative as a measure of cost, but against the term for recouping costs, it's very expensive. Without ads, this wouldn't be a viable business.