For that to work you need to get the spread down to workable numbers again, which hasn't happened with the current lock down. It's in the limbo of too harsh to actually use the medical resources but too light to set it on a quickly lowering path with a workable timescale.
If 5-10% has it you can essentially just assume everyone has been in contact within 1 or 2 steps with someone who has it, no need for fancy privacy invading tracing.
Testing is good to catch people early, but if the capacity isn't here 2 months after the Italian outbreak, when will it be?
I can only speak for San Francisco (and to a lesser extent the Bay Area): we do have workable numbers at this point. Approximately 150 new cases reported per day and declining. Our testing is also ramping up relatively quickly, especially in SF, and so is training for contact tracers. The mayor is planning for mid-May to start reopening, as a result of these numbers.
The Bay Area has high testing and contact tracing ability. As an extreme, Santa Clara County (just south of Tesla) is at a 1.5% weekly positive rate and contact tracing every positive.
I mean, tragically, testing capacity in this country may never be where it needs to be, because we don't have an election coming up soon enough to replace our incompetent leadership in time to help.
But that doesn't mean we shouldn't push back on the claim that the only two options are uncontrolled spread and never ending lockdown. There is another way, it isn't hypothetical, it is being executed elsewhere. We just aren't taking that path.
Oh I think I see your perspective now. Yes, if you don't believe a vaccine will be developed then I can see where you're skeptical of the end game of testing and tracing.
But your certainty of the unlikelihood of a vaccine is far too strong far too early. There are on the order of ten to a hundred promising efforts toward developing a vaccine well under way. It may very well be that a year or two from now, each of those will have failed. If that is the case I will be open to hearing about how best to manage this indefinitely, and you may be right that testing and tracing won't help that much (but it still seems like we may want to control the order and rate at which people are exposed).
But we're really far from having the evidence to support your claim with any certainty. We haven't run out of ideas for how to make a vaccine yet, we're just getting started.
If 5-10% has it you can essentially just assume everyone has been in contact within 1 or 2 steps with someone who has it, no need for fancy privacy invading tracing.
Testing is good to catch people early, but if the capacity isn't here 2 months after the Italian outbreak, when will it be?