Correction: HGST/Hitachi
** "There’s also Hitachi (owned by Western Digital)" **
Um, no. Not quite.
Hitachi Global Storage Technologies was created by an IBM/Hitachi drive tech business merger in 2003.
WD acquired the business in 2012 and rebranded it as HGST and from that time, it had absolutely nothing to do with Hitachi.
WD does not own Hitachi.