A specific piece of advice is circulating right now, repeated at conferences and sold as an ebook by people who have made money selling the ebook: quit your job, start a blog, and within a year you can earn a living from advertising and affiliate links.
The evidence offered for this is always the same handful of names. A handful of technology and lifestyle blogs that genuinely do generate serious revenue, run by people who are, without exception, extremely good at this specific and unusual combination of writing quickly, understanding an audience, and building an advertising relationship. Those sites are real, and their income is real.
What almost never accompanies the pitch is a number for how many people tried the same thing and made nothing.
I don’t have a precise figure, and I doubt anyone selling the advice does either, because it would undercut the pitch. What I do have is enough time spent reading blog directories and abandoned archives to say with confidence that the ratio of blogs that generate a living wage to blogs that generate nothing essentially is not close, and that the failures simply stop posting and vanish from view rather than writing a public post-mortem, which means the population anyone actually sees skews permanently toward the survivors.
That is the exact mechanism survivorship bias runs on in every domain it shows up in. You only get to study the ones still standing, and the ones still standing didn’t necessarily do anything replicable; they were often simply first, lucky in timing, or building on an audience assembled somewhere else before blogging was even the product.
None of which means blogging is worthless or that nobody should try it. Plenty of sites that make no money are still worth running for reasons that have nothing to do with income: a portfolio, a way of thinking in public, an audience of a few hundred people who genuinely value it. Those are legitimate reasons to write.
What is not legitimate is presenting the top handful of outliers as a realistic outcome and letting people conclude that quitting a salary to pursue it is a reasonable bet, rather than what it actually is: closer to a lottery ticket with better production values.