JNot sure if the flash is “gone”, the drive does still believe it has 256GB. I have seen drives die to where they completely forget their identity and are now “Phison controller with 32KB storage”. All they have left is either some absurd concept of falling back to using the controller’s on-die EEPROM, or they’re telling you they have the smallest possible CHS size that isn’t 0 just as a courtesy.
But yeah, the drive does look too mentally broken to continue.