I think only social distancing is necessary.
If the healthy under-40s caught it, they’d almost certainly not die. Look at the figures.
And what would your suggestion be? How long do you think we should stay inside for?
Ok - if you're under 40 are you one of those happy to take the risk of 'almost certainly not' ?
How do you maintain social distancing to the levels necessary to get R below 1 without lockdown ?? We sort of tried that in the few days before lockdown - look at what happened on the tube, parks, beaches, beauty spots etc etc .All mobbed.
We'll start to have a gradual release - 'lockdown' doesn't have to be all or nothing, but it did have to be for a time stop the NHS being swamped. That at least has worked so far and is hopefully coming to an end.