I sometimes think that the only ones still employed are working in medical communications. *Everything* in medicine that might expose a company to liability -- which is virtually everything -- goes through two proofreaders. And they're among the best I've seen in my 35 years in the business.
As for the rest of publishing, I think you're right. It makes my teeth hurt to read expensive books and to find errors, which my old editor's eyes tend to be drawn to like a pig finding truffles. Sometimes I think they aren't even using spellchuckers.