Yes very good point. However, as @danbruc rightly points out this raises all sorts of other concerns. A user of these IDs my not realize that the reliability of the ordering can be substantially reduced depending on where the IDs are generated.

Some applications may be able to tolerate inconsistencies in ordering, others may not. Are IDs being generated on multiple machines? Are they in sync? What happens if the system clock is adjusted, or a container/VM is restarted on different hardware?

This design implies that these IDs are being generated in different locations, but this usage leads to the least reliable time. How many bits of approximate time does one really need? Not 48 surly.

On the other hand if you generate the IDs in the most reliable model, a single host with persistent storage to prevent regression, you've basically made an unnecessarily complicated vector clock. A simple incremental counter would work at least as well, and be far simpler.