* Advertising revenue is practically nonexistent today compared to its heyday in the late 90s. This is because a few key players like Google have created a monopoly/oligopoly where they are so large, with so much more personal information on everybody, that they keep much of the profit for themselves and squeeze out any competition.
* The internet still provides lucrative careers for many, but this is in spite of (not due to) monopolistic players like Google. In other words, we'd all profit more, and have more room to innovate, if the big players like Google, Apple, Facebook, Amazon, etc didn't control nearly every aspect of the internet.
* Google is several orders of magnitude bigger than anyone's conception of how big it is. Short of a national monopoly breakup campaign, this will have little to no effect on their profitability or hiring.
My personal feeling is that income inequality largely stems from the US no longer enforcing antitrust laws, consumer protection laws, or finance laws like the Glass–Steagall Act. It effects liberals and conservatives alike and leads to global threats like nationalism (a leading contender for World War III) when the vast majority of the population spends so much time working to make rent that it's effectively disenfranchised, no longer has upward mobility/retirement, and doesn't have the means to raise a family.