I've only taken SYD-BKK in J a couple of times since the end of BKK-LHR service, but flights were sold out in J each time, fwiw (and not full in Y). Still hard to keep a ground station for such few flights esp. with not much cargo. Suspect QF hung on for so long either because it had new leases on the lounge space or as an alternate hub to HKG or SIN for an Asian J service (which was a pipedream by Joyce). QF chose not to partner with AY who do fly HEL-BKK/HKG which could have augmented EK but apparently not what EK had in mind
QF had abandoned KUL years ago and partners with EK to KUL instead of with MH; Oneworld is like that. Actually the EK partnership is pretty good for FF status.