Honestly if people want good competition between Epic and Steam, paying for exclusivity to one platform, timed or not, is definitely not the way to go about it, especially not on PC.  What they should be doing instead is make their own games and sell them exclusively on their platform, and then ask devs to put games on their platform that are also on Steam.  Another thing to do is make your platform consumer friendly, instead of just dev friendly.  An example would be a few of Steams features, such as customer reviews, or the Workshop for modding, or built in forums.  Right now, Steam beats Epic hands down in terms of being customer friendly.