Earlier quoted context omitted.
Don't forget, Twitch bought Curse, a company known for catering to gamers: - the longtime Curse Client, effectively an addon manager that started for World of Warcraft but now supports games like Rift, Skyrim, Minecraft, Kerbal Space Program - CurseForge, the community site behind addon hosting and development - the recent "Curse Voice" VOIP and chat client that is a direct competitor to Discord, and which got subsum…
Steam has so much value add beyond just its storefront, which is still the biggest in gaming. The community features are the most important - being able to see who's playing what and more importantly, being able to join their server, is not possible (yet) with Curse/Twitch. A lot of the Curse stuff is honestly little value, and if we're keeping track, implemented in Steam already. Curse Voice = Steam's in-game calls…
To name a few: cloud saves, steam workshop, big picture, and steam controller.
Even if I dropped all the social features in favor of some other platform, I'd still be launching all my games through steam for those features alone.