Fair enough. In the telemetry world the second case you mention is rarely seen. I'm sure someone, somewhere is doing something like that, so I won't say never. In flight testing you have anywhere from a few measurements to thousands of measurements gathered from physical transducers, and then digital data bus information that can vary dramatically from platform to platform, from just a few kilobytes/sec to gigabytes/sec.
There's many, many cases where you have lots of discrete inputs but a lower time threshold. In/out bytes per port on switches in a datacenter. CPU/memory/disk stats on virts you spin up for on-demand load, or just your normal datacenter deployment. Employees/vehicle locations in the field. Often you don't even need per-second time granularity, but that can be made up for with a larger number of discrete inputs (how many trucks does UPS have in service?)