

All of your temporary privacy addresses will be coming out of the same subnet, so it’s clear they all belong to the same people.
Ultimately the privacy extensions are just bringing IPv6’s privacy back in line with IPv4, because without the privacy extensions every single device has a separate IPv6 address based on its MAC address whereas in IPv4 most consumer networks have every device sharing a single IP.
“You wouldn’t download a car” is a meme edit that got stuck in everyone’s heads. The original PSA actually does say “you wouldn’t steal a car” and basically was what you describe in your last paragraph.
https://youtu.be/P-pYiWGSN8w