OpenStreetMap costs a few hundred thousand dollars a year to run. Wikipedia is about $3 million. Redditors are cheap, but you can have a backend doing the heavy lifting for a community (assuming mods work for free) at a cost that can be sustained with a small pool of financial contributors.
> VCs to continue to pour hundreds of millions of dollars to run the site and never ask for an ROI
None of this needs to cost hundreds of millions of dollars.