A lucky Reddit user who happened to receive their Xbox Series S console a week early states that it only comes with 364GB of usable storage. That, combined with a lack of a disc drive, will make it difficult for users to simultaneously store more than a few games on the console.
https://www.notebookcheck.net/The-Xbox-Series-S-allegedly-comes-with-a-paltry-364GB-of-usable-storage.502168.0.html