The first line in the article states
"Advertising is the critical financial engine of the Internet"
wrong
Advertising is one of the ways we pay for the Internet. To people in marketing and sales it is important, but it is not the critical financial engine of the Internet. My guess of the most important revenue areas would include the fees paid to ISPs for physical connection, the devices we use to connect ourselves to the Internet and the content for which we pay (such as games, services like SalesForce, Confluence, etc). I do not have the figures but expect advertising revenue is relatively small compared to these other broad areas. Advertising is more about redirecting expenditure, or dividing the pie, rather than making the pie.
Kevin