It doesn't hurt that millions already use Epic's launcher to play Fortnite, either. As a result, a number of developers and publishers agreed to exclusive launches on the Epic Store. Metro Exodus is the most notable example, as it took preorders for months on Steam before going exclusive...
I could get above 100fps during exploration and almost 200fps during space combat, but there were constant stutters. Nvidia's RTX Direct Lighting also exhibited some issues, and the performance hit for a minor improvement to its visuals isn't worth it....