I’d suggest that the title should be, “Competition for Google AdWords is so strong that unsophisticated advertisers can no longer get a good return. Where do I promote my business now?”
Nobody goes there any more. It's too crowded.
-- Yogi Berra
I have a feeling that it is mostly unsophisticated advertisers bidding up the price of AdWords.
it's not "competition"
it's bots creating too high noise-to-ratio for feedback loop
He had presumably used it for 10 years successfully. Surely he gained some expertise over that time period.