1. A computer-implemented method for hotspot mitigation in object-based file systems, at least a portion of the method being performed by a computing device comprising at least one processor, the method comprising: identifying a storage system comprising a plurality of storage devices; identifying an object stored on a storage device within the plurality of storage devices; identifying a level of demand to access the object; creating, based at least in part on the level of demand, a number of sparse object to represent the object on at least one alternate storage device in the plurality of storage devices, wherein each sparse object is populated with data corresponding to the object on a just-in-time basis in response to a read request; for each sparse object, generating a unique shadow map that locates the object at a unique location of the sparse object; fulfilling at least one attempt by a client to read from the object by serving one of the unique shadow maps to the client resulting in reading the object via one of the number of sparse objects.