Epic Games Online Services v.s Improbable SpatialOS for Large Multiplayer or Battle Royale Games

Hi, I was wondering if anyone here can explain when would it be better to use Epic Games Online Services as opposed to Improbables SpatialOS for building large MMO’s/Battle Royale games like Fortnite or large Multiplayer Games like Call of Duty and Halo. In terms of cost and development time, which would be better? Which is easier for a small dev team wanting to build a large game? I know Epic Games Online Services is new and many other games have failed even with SpatialOS, but games can fail with either platform so I am just wondering how you would decide on which platform to use for your large multiplayer or battle royale type game. Thanks.

EOS and SpatialOS do different things, one doesn’t replace the other