Sadly, most of the tests with fast results are highly inaccurate. Their false positive rate is way, way too high. You’d get way too many people who are tagged a

Sadly, most of the tests with fast results are highly inaccurate. Their false positive rate is way, way too high. You’d get way too many people who are tagged as being positive and kept from traveling (or whatever), which would create another crisis of its own. Contact tracing only works for you if every person you’ve been in contact with is willing to participate. And that assumes you actually know all of the people you’ve spent enough time around to be considered to have contacted them.