In the end ,not he government has to weigh the negative outcomes of all these options and choose the one which is least bad for the majority.
If the NHS gets filled up with Covid patients and cannot take any more and cannot care for those with cancer and heart attacks and road accident injuries and all the household injuries that happen every day, then the health if the nation will drop dramatically now and into the longer term. This in itself has further economic consequences and consequences for inequality as it will all hit the less well off worse.
They have to weigh this issue against people wanting to send their kids to school, to go to work and to not be isolated. They have to think about the short term and long term consequences.
Individuals tend to think about their personal situation and the short term impacts, rather than the bigger picture and longer term consequences. It's normal to think like that but the job if government to look at the bigger issues.
There is a point where the consequences of healthcare failure will override the other issues. They will have to. The government mig have to stop most people going to work or hardly anyone going to school and to say all but the mist extreme cases cannot see people outside their household...for a period of time. And this will mean that cases don't rise at the rates they are or prevent anyone having other health issues getting treated.
These are hard choices for a government who doesn't like to infringe civil liberties. But it's their job to make them.
Most people are roughly sticking to a loose interpretation of the rules at the moment. But the rules aren't clear enough or tight enough. In a week, an individual can see and chat with numerous people and still be roughly within the rules. It's too many contacts to prevent the spread of a highly infectious disease.
Just count up how many people you have seen and spoken to this week - on walks, in houses, in shops, at the door, at work, on school run. Total them up. And consider how many people each of them also saw. This is how it spreads.