Covid further ratcheted up my hopelessness in people's ability to maintain the most basic grasp on how reality works. But in the early days, it was insanity-inducing to try and reason with friends who though the solution was a super-easy "just have every single person lock themselves inside with 100% compliance for two weeks and poof".
It's an unfortunate consequence of the complexity that allowed society to become so unimaginably rich that many people are so detached from the reality of what it takes to make everything work; it's even more unfortunate that these people vote.
For 3-5, even if "lock down for 3 weeks" can't literally stop all cases, it still sounds like it could have been achievable to bring them back down to the level where track-and-trace could be effective, and China's efforts would be much more successful than they have been.
And it's not just these people. It's all the people providing the services they need to do their jobs. Police station cooks. Ambulance mechanics. Hospital laundry staff. Couriers delivering spares to power stations. And the people they depend on: catering suppliers, cleaning supplies wholesalers, warehouses. And so on, the transitive closure of everyone depended on by essential workers. Which, because of the ramified and interconnected nature of a modern economy, is a substantial fraction of everyone.
Secondly, because even if you did that, not everyone would do that. Some people would break the lockdown to see their dying relatives, suicidal friends, starving neighbours, star-crossed loves, bridge partners, etc.
Thirdly, because even if they didn't, you're locking down whole households, and you can get serial transmission between individuals in a household, so SARS-CoV-2 can last longer than three weeks, it can last about two weeks times the number of people in the household (assuming there are no reinfections).
Fourthly, because even if it didn't, somehow you blocked intra-household transmission, in a handful of cases, infections can last longer than three weeks in a single person.
Fifthly, because even if they never did, SARS-CoV-2 has several animal reservoirs in wild species which live in close proximity to humans.
The idea of "three weeks to stop COVID" was always an absolute fantasy, and honestly, very obviously an absolute fantasy. I am not an expert on viruses, epidemiology, logistics, public health, anything like that. But i read the news and i thought about it for a few minutes. What i don't understand is how so many other people didn't.