The trouble is that traditionally, I think the permanent Bluetooth MAC was how phones knew to reconnect with devices like headphones so it couldn't easily be randomized. This was all designed in an era when people were less paranoid about how tech could be abused.
Its probably fair to say that tech was less abused in that era, not that people were less paranoid about it. Your run of the mill telemetry would have been considered spyware (a term that's nearly dead) back in the day.
