I don't think stopping the spread is unreasonable or incredibly difficult. It's being done in HK, Singapore, and Taiwan now. First you lock down to get cases

I don't think stopping the spread is unreasonable or incredibly difficult. It's being done in HK, Singapore, and Taiwan now. First you lock down to get cases to roughly single digits, then people come out, but it's different. The trick is you need to get R0<1, so that when a new case pops up, it dies out instead of blowing up. You do that with mask wearing, hygiene, aggressive contact tracing, broad scale testing, and strict isolation. You keep people alive that get the virus by having good medical care. The aggressive contact tracing, isolation, and good medical care don't scale. If you have only dozens of cases, you can afford to aggressively isolate and put a lot of manpower into tracing every case. You give the virus no breathing room. If there aren't too many people needing medical care, you can also provide them much better care. This is why you need the lockdown -- to get R0<<1, to bring down the case count dramatically so that these other measures can work. We could have just started with Phase 2 outside of China, but we didn't spin up all of the things that you need for Phase 2 in time. The countries that are doing the best had previous SARS experience, which was successfully eradicated with these measures, so they knew what to do right away and were institutionally prepared to act quickly.