https://wccftech.com/valve-steam-epic-exclusivity-comments-lightning-rod/

For the most part, Valve has remained fairly quiet about the new competition they face from the Epic Games Store, even as multiple high-profile PC games have been lured away from Steam. The only time Valve really fired back was when Metro Exodus was poached by Epic only a few weeks before the game’s launch. In response, Valve left the following message on the Metro Exodus Steam page:

Sales of Metro Exodus have been discontinued on Steam due to a publisher decision to make the game exclusive to another PC store. […] We think the decision to remove the game is unfair to Steam customers, especially after a long pre-sale period. We apologize to Steam customers that were expecting it to be available for sale through the February 15th release date, but we were only recently informed of the decision and given limited time to let everyone know.