To take another country which is entirely different to ours: New Zealand. Population 4.9m with a density of 15/km2: even less than Sweden.I think a precautionary light lockdown was OK, I think we should be out of it almost completely now.
BUT it's held up as a success because they eliminated the virus. How? Lockdown.
Two papers (there are others and it's difficult to find credible opinion to the contrary) here and here suggest that early and aggressive lockdown was the key. They took the opposite approach to the majority of countries and have had the most success. But yes, like Sweden, they're nothing like the UK.....
However, something to think about: Johnson/Cummings initially were pro-herd immunity or a very light lockdown along the lines you suggest. They're libertarians at heart and all through this they've been unwilling to put measures in place and unwilling to enforce them once they were in place. I remember seeing him physically recoil at the suggestion that the police might be involved in enforcing lockdown measures! BUT something spooked them and they went for lockdown. So what was that? Perhaps they listened to the immunologists/WHO et al. Perhaps, when it boiled down to it, faced with the choice of crashing the economy or having half a million (and that's what they were predicting, more or less, right or wrong, at the time) dead on your hands, they couldn't face being responsible that sort of carnage. It might turn out that the predictions were wrong (they seem to be off, it's a matter of by how much) but faced with the figures at the time, I think lockdown seemed the only answer. It also seems to have provided a useful source of profit for Johnsons/Cummings friends, the disaster capitalists.
But it seems to have worked. More or less. And it would have worked better with an actual, operative, track and trace system during the height of infections (look at China), perhaps meaning that a lighter lockdown might have been possible.
But this is all hypotheticals. Perhaps the truth will come out in the Public Enquiry. I'm not holding my breath.
