Those who have control in government set the rules up as they see fit. If Apple and Google don’t support a method to do this, they will be pushed by law to do it differently. If your problem is that something will be made mandatory, either change the law or find a loophole, as anyone else would have to. The current implementation, at least for Apple, is 100% optional, even if you have an app installed allowed to read this data, you can still turn it off in settings. If the point you’re making is that PRISM existed, and therefore SV can’t be trusted, outside of abolishing the NSA, what would actually fix this? The problem is one of legislation, not technology. And it’s worth pointing out that if you’re this afraid of tracking, you should probably set your phone to voicemail and turn on airplane mode on a regular basis. Your ISP knows what devices you have, and where they are. This doesn’t change that. Besides, even without Apple and Google, governments are inventing apps. So I fail to see how tech companies proposing a less-privacy-invading-option is harmful? Would you prefer tech companies outright lied, were caught lying and then had to implement a worse solution anyway? The law is the law... tech companies don’t themselves make it, they just propose the rules for their walled garden within what the law allows.
For me SV of the past some years or so has and not even started to repair that trust.
I don’t think your phone logging proximity to every phone it’s been near is similar to browser cookies.
Historically, I’m skeptical that it won’t almost immediately be abused and will remain optional.
There is no going back from a government sponsored, first party system like this. So there is no need to rush in now.