Phison rocks the storage world with the world’s first 128TB class PCIe 5.0 SSD

No, because that would be an easily overcome hurdle by just adding a little extra silicon in each unit to ensure that it meets or exceeds the advertised capacity if the manufacturer were not in fact actually interested in being deliberately misleading. This thing appears to kind of be an exception, but even then they're allergic to just outright stating the capacity.

If the manufacturers were interested in being honest with these types of things the "size class" would not so often invariably, unfailingly, result in a generous rounding up of the stated figure rather than rounding down.

TV's are always smaller than their advertised "size class." Appliances are always a lesser capacity than their advertised "size class." Cameras always have fewer pixels than their "megapixel class." Storage media is always smaller capacity than its advertised "size class."

(And this is before we even get into the whole megabyte-gigabyte-terabyte/mebibyte-gigibyte-tebibyte debate.)