Re: Yet another elastoplast with unexpected consequences?
There are several ways to use static MAC addresses to track.
One is that it allows the WiFi provider (hotel, store, shopping mall, local authority) to track your movement and usage and correlate it with what you did yesterday, and last week. If last week you accessed an Extinction Rebellion web page (or a protest app since made illegal in Hong Kong), they can make sure that this week you are not allowed into the mall (or arrested).
A second reason is that it provides a long term identifier available to applications, which they can use for gathering and correlating personally identifiable data. Apple have made it possible for users to change their marketing ID (and Android claim to have recently done the same, although I trust Google less than Apple), but the MAC address provides apps with an alternative long term identifier, particularly if they can get assistance from a device on the same LAN (for example an advertising hoarding, or an access point provided by the mall owner) which sees the MAC address used in traffic.
Sorry, but fixed MAC address are a personal tracking device.