This means that the scalability advantages of tech don't synergize well with the uses of contact tracing. If you don't have very many cases to worry about, a dedicated team of humans will do just as well. And not have nearly the same long-term privacy issues.
That seems unlikely to me given that no jurisdiction has unlimited resources, not everything is captured on camera, patient's memories aren't perfect, and there may be incentives to lie or otherwise under-report certain contacts when things aren't completely anonymous. (For example, in many countries patients are likely to avoid revealing contact with a drug dealer.)
In comparison, DP-3T (and also the joint Apple-Google framework based on an earlier revision of it) will capture any significant contact provided that both parties are carrying appropriate devices. It also maintains anonymity, so it removes nearly all incentives to mis- or under- report. It's not a replacement for teams of people, but it should provide significant improvements in areas where the majority of people are carrying such devices.
> And not have nearly the same long-term privacy issues.
Neither DP-3T, the Apple-Google framework, or the TCN protocol have any significant privacy implications (beyond whatever is already associated with carrying the physical device doing the tracing, and to the best of my knowledge of course).
As to Iceland's 40% uptake, their app isn't anonymous - in the event you test positive you share your full location data with the people doing the contact tracing. It's also not built into the operating system so there's more friction for user uptake.
At very low case rates, the overhead and required adoption rates for an app-based tracing system are major disadvantages against human contact tracers. As case rates go up, that overhead starts to pay off and apps make sense. But as case rates continue to go up further, you get less and less information from contact tracing. At some point, when case rates are high enough, it basically becomes a single bit of information: did you go out? Yes? Then you were probably exposed. At that point, the app isn't adding much value!
I believe that in many places around the world dealing with COVID-19, we are closer to the latter scenario than a lot of people think. No, we're not literally in the scenario above (it was an exemplar), but the general point that case rates may be too high for contact tracing to "save us" is still worth making.
One thing the app might be used for is to allow visitors in without quarantine. Prove you have tested negative recently and use the app so if you do get sick we at least have a vague idea of where you were.
If the place you went to doesn't have the sanitiser part then they're probably breaching their public health obligations. You can ask them to put out sanitiser or report a breach.
https://forms.police.govt.nz/forms/covid-19-breach
As an aside, I'm impressed in NZ that there's a central place to report issues but then issues are dispatched to the right agency to follow up. That makes it super easy to report issues.
[0] https://www.stuff.co.nz/national/300016238/nz-covid-tracer-w...