https://www.gamespot.com/articles/fallout-76-wont-be-available-on-steam/1100-6460988/

One of 2018's biggest games, Fallout 76, will not be available to buy on the world's largest PC game store--at least not at launch. A Bethesda spokesperson told PC Gamer that the upcoming beta and the full game for PC will be exclusively available on Bethesda's own website, not Steam.

"The PC version of Fallout 76, for both the B.E.T.A. and the launch, will be available only via Bethesda.net, not on Steam," a Bethesda representative said. Bethesda marketing executive Pete Hines also tweeted about the Bethesda.net exclusivity for Fallout 76.