There was a static universal device identifier until iOS 6. Even today, while Apple has implemented many sensible restrictions on tracking, there's still a ton of information that can be used for device fingerprinting freely available to all apps. This blog post [0] pegs the amount of useful information at around 56 bits.
Totally! All too often cars have a direct route from point A to point B while cyclists have to wind through complicated, low-speed side roads with little or no signage to help.
That said, I think Portland has done a great job with the signage part of this problem. Signs like [1] are present at just about every intersection of bike routes, giving directions to neighborhoods and landmarks. And when a bike route dog-legs, directional "sharrow" symbols [2] are clearly visible on the road surface.
[0]: https://nshipster.com/device-identifiers/#fingerprinting-in-...