nitaaikumar Wordpress.com (free with ads) and Medium (free with no ads) have more reasonable prices than Ghost, not based on monthly pageviews, so they are thriving somewhat. I think Flarum's present transparent donation-based system on opencollective has great potential to thrive a lot if more and more people install flarum once it is stable.
Just FYI, Wordpress..com is not associated with the Wordpress foundation, it's a separate for-profit entity. It's easily confused, but any money you spend on Wordpress.com does not necessarily go toward the development of Wordpress itself.
Our donation model through OpenCollective is purely to support the software development (and the legal foundation that protects it). That's different from selling a managed service like Ghost (or Discourse, for another example) is doing as a first-party service. There was some attempts to do that for Flarum itself a few years ago, but were closed in the testing stages to ensure the focus was on delivering a stable software product.
So there's really three things going on here, and they seem to be getting confused. First, there are third-party paid services for managed hosting of the software (like Wordpress.com), then there are first-party paid services for managed hosting of the software (like Ghost or Discourse do through their official sites), and then there's just straight-up donation to the software project itself (like Flarum or Wordpress.org does).