Once you have large scale testing available, you can do heavy testing in a region to determine the risk, and then you can release quarantine on regions where th

Once you have large scale testing available, you can do heavy testing in a region to determine the risk, and then you can release quarantine on regions where there are no infections. Control is much easier if testing is cheap and ubiquitous, and quarantines can start to become a lot more targeted as opposed to widespread.