Yes hindsight is a wonderful thing isn't it?
Bring a lockdown in earlier and sudden thus probably causing mass riots and looting and more people being unemployed now because the job retention scheme wouldn't have been ready or possibly even thought of.
Why do people still think this lockdown is on place to fight the virus? It was never the case and no government official ever said so. Lockdown is to slow down the spread of the virus.
It's not really hindsight though is it, as this was all known with relative accuracy. We're on the exact same path as others, except we're delayed behind them and have more notice. It doesn't take a rocket scientist to listen to the WHO, do the same as the countries doing well, that had been in situations like this before, and listen to those experienced (that were all saying, test, isolate, trace, lockdown etc).
Nobody in the world was saying keep all the pubs and shops open, go for the herd immunity option, you will all be fine. They had people stood on doors, checking peoples temperature before they went into areas the disease could spread.
Riots and looting? From whom and why? Nobody is saying send the police to the other side of the world, and we do have an army, which likely wouldn't have been necessary, like it wasn't necessary in the other civilised places that locked down, traced and tested early.
It would have just been the same as it was, just two weeks earlier, no bog roll and no pasta. This could have been stopped also if the supermarkets had put actions in place, that they would have noticed within a day.
The job retention scheme was obviously a quick idea that hadn't been finalised. Other countries carried out similar measures and if we had locked down earlier we could have been out of it earlier, and certainly with less deaths.
Lockdown reduces the R number, which is to slow the spread, which is the number one way to fight or stop a virus and massively reduces the death toll. The other option being testing everyone and shooting people that have it on the spot.