Look, I'm not defending wikipedia, I'd just like to point out that comparing hosting to salaries is a quite strange metric. Hosting is cheap and relatively constant, adding features to the site or paying admins to maintain the quality of edits is scalable. How does throwing more money at hosting make a better product? It's not like the servers can't handle the requests.

Using hosting costs as an index is nonsensical. I wasn't able to find numbers for 2009, but since 2015 the monthly page views have remained almost exactly constant. So you might as well claim that they're vastly overpaying for hosting since inflation from 2008 is way less than 3.75x.