I feel that Apple and Google are a bit coy when they claim their solution is opt-in only. Given that one super-spreader can infect a whole city, you need very comprehensive coverage to keep infections under control. It's as if these companies are winking at governments and saying: Hey, we've done our part, now it's on you to enact CCP-style policies to make sure that everyone has to opt-in before you're allowed to leave your hose.
