Which is exactly why using standard Unix/POSIX files makes sense as a universal interface for genomics programs that are run in highly heterogeneous environments across the world, even if it leads to software engineers wishing that their internal custom data storage systems were used instead.
If random access is needed in a cloud environment, use either that local ephemeral SSD, or a cloud block device which is probably just an iSCSI implementation underneath, or at least a close equivalent.
Operating fleets of compute and IO in cloud environments means that POSIX semantics generally work really well for genomics.
Folks that have reimplemented basic genomics algorithms on top of protocol buffers standardized serialization still store them as BLOBs, and have not delivered benefits that can be realized in publicly available compute environments.