Helium can leak into and between crystals in the metal inside the container and container itself. That process changes dimensions and mechanical properties of construction.
In this particular case I see it as a planned deprecation, sort of.
In this particular case I see it as a planned deprecation, sort of.
It would be a disconcertingly new phenomenon to find every drive in some old archival NAS failed simultaneously, or every one In a collection of external drives, because all drives last exactly 5 years with little variation, even when switched off, due to helium loss.