I like the peer comment's answer about a processing time threshold (e.g., a day). Another obvious threshold is data that doesn't conveniently fit on local disks. Large scale processing solutions can often process directly from/to object stores like S3. And if it's running inside the same provider (e.g., AWS in the case of S3), data can often be streamed much faster than with local SSDs. 10GB/s has been available for a decade or more, and I think 100GB/s is available these days.