Most of these applications depend on OS optimizations that have been made over the decades; multithreaded readers, readahead, and caching are critically important to read performance. In principle, a remote storage system could be as fast as a local disk. This includes random access. after all, the storage system is just a bunch of drives attached to machines connected by networks.

When I worked at Google I wrote a mapreduce that converted BAM files to sstables which are sorted, sharded by key, and sit in an object store like S3. Once the files were in sstables (or columnio) we could do realtime analytics using modern tools.