For example, I spent years on Reddit happily arguing with wrong people, deriving my "value" from just having fun interacting with folks about stuff. The server resources that Reddit expended supporting that were fairly trivial in dollar terms. [...] Instead Reddit hired 2000 staff for some reason
They hired 2000 staff because they were running one of the most highly-trafficked websites on the Internet, with hundreds of millions of users, something which unsurprisingly takes quite a lot of people to administer and maintain. Were Reddit to not invest in people and resources to keep the website running at that scale, you would not be able to use it in the way you enjoy and it would have nowhere near as much utility to you.
This is the entire point of the article that you missed - there are a shit-ton of costs in running a massive community that have to come from somewhere. Your approach is "well I don't think those costs are necessary". But they are.