I’ve looked at the details of Apple and Google’s joint contact-tracing effort and I have to say, I think it is going to fail to make much, if any, difference.
They are going to absolutely nail the fundamentals, except for the part about actually verifying when someone has tested positive. There is going to be no standard for that.
In fact any piece that relies on the private health system make correct design choices and provide clear data and standards will fall flat on its face. People will spuriously self-report as positive, whether by accident or through idle malice.
The system will end up being useless.