If we do end up implementing a centralized contact tracing system, the results will be very interesting. I would love to know the name and location of every lobbyist that my elected representatives have met with, and I'm sure that in the name of public health they won't make any efforts to thwart this tracking.
In that case the governments do not need this silly contact tracing app. They can just use the data they already have.
We were required to sell the data to the government on demand due to CALEA and similar legislation.
Those who complain endlessly about AANG largely seem to have no idea of how our communications networks actually work. Your location, activities, banking, etc. are not private, will never be private, have never been private, and it has nothing to do with AANG. The 3 AANG that I have worked are woolly lambs. That F guy is a bit suspicious, but I don't have first hand knowledge.
You need to have enough people for that, you need to have the testing capacity and you need to have people following that order.
It will work well if you have very low community spread and can start tracing on cluster level. If you are not there it can still be a good tool but you would probably still need a lot of other restrictions as well.
I've worked at a telco where we were analysing customer's behaviours and almost everyone follows a pattern at some point e.g. going from home, via public transport to work. The resolution isn't high but over time you build up enough samples to accurately determine exactly where they live, work etc.