> No print publication on the planet does this

At least in India, most popular newspapers actually do this nowadays. Several full page ads including on the front page have become the norm.

It is mostly a function of how little the reader is willing to pay for content. When the price point is too low (which for online content is too low), publishers make their money by other means. It is not rocket science.

A lot of print publications used to do it, and many still do.

Print magazines make most of their money from ad sales, not subscriptions. A typical ratio is 60:40 ads vs editorial. Magazines like Vogue go >70% ads, and I'm fairly sure old issues of Byte and other computer magazines were in that ballpark.

The difference in print is that the ads are targeted, and even welcome. Many of the ads in old computer magazines were price lists and mini-brochures, and pre-web that was the only way to get that information to customers.