I understand his argument about gatekeepers, but Steam is a poor example. Steam itself provides so much more than a simple storefront as he describes it. By selling on Steam you also get
Steam API, which gives you
- Achievements
- Leaderboards
- Cloud save
- Steam Workshop - user generated mods and content
- Multiplayer infrastructure
Steam community, which gives you
- Forum
- Social network - user generated content such as screenshots, game guides and fanart
- Reviews - endorsements from several thousand actual players sells games far better than a flashy trailer
Whether these features are worth the 30% cut is arguable, but these services are far more valuable to independent developers, who don't have the time or ability to implement these, than to developers under large publishers, who may share these infrastructure within the games they publish.
Steam API, which gives you
- Achievements
- Leaderboards
- Cloud save
- Steam Workshop - user generated mods and content
- Multiplayer infrastructure
Steam community, which gives you
- Forum
- Social network - user generated content such as screenshots, game guides and fanart
- Reviews - endorsements from several thousand actual players sells games far better than a flashy trailer
Whether these features are worth the 30% cut is arguable, but these services are far more valuable to independent developers, who don't have the time or ability to implement these, than to developers under large publishers, who may share these infrastructure within the games they publish.