It's more the fact that MAC addresses have an inherent ability to track you, and many such companion devices you might interact with are in fixed locations.

Modern security conscious Wifi devices address this by randomising MAC addresses - they're no longer fixed for wifi. You can even configure different wifi networks to have randomised per-connection or per-network (default per-connection), so you can still set up MAC filtering easily.

Bluetooth unfortunately requires fixed MAC addresses as a core part of its pairing functionality. What's more many connections can require you to provide bluetooth contact data - the same data used for covid contact tracing - eg Ford's implementation of Android Auto among others.

So your car might not only be tracking you with its internal GPS and cellular 4G connection, it also wants to know wherever you go with your phone, based on the Bluetooth LE devices you ping.

As such you should turn your bluetooth off whenever you're not using it.