They have taken the wrong approach.
The differentiator should be the launcher/store not the exclusives. Snatching up 3rd party exclusives I consider vile and very anti consumer.
Really they should have done this and early on as well.
Achievements, Libraries, Shopping Cart, Reviews and other steam feature parity.
Added social media integration, twitch, youtube, discord etc.
Added achievement points to store points feature.
Added allow rollback game patch feature. (control in hands of user not dev).
Thats a starter point, my point is there is areas steam is lacking, its not a perfect product, and these features would make it standout rather than just nabbing store rights and forcing people to use their launcher if they want to play specific games.
Even today years after its launch its lacking in many basic features.
The sad thing is epic seem stuck on the wrong path, they still filing new court cases because they want to use their own launcher on every platform, and are still nabbing exclusives even though its proven unpopular and unprofitable.