So much misinformation on this thread.
The UK govt's starting assumption is that a high number of the population will inevitably get infected whatever is done – up to 80%. As you can’t stop it, so it is best to manage it. There are limited health resources so the aim is to manage the flow of the seriously ill to these. We're aiming for herd immunity which will protect the most vulnerable.
So at the moment the govt wants people to get infected, up until hospitals begin to reach capacity. At that they want to reduce, but not stop infection rate. Ideally they balance it so the numbers entering hospital = the number leaving.
That's apparently why we've not closed schools yet, it's too early. Kids generally won’t get very ill, so the govt can use them as a tool to infect others when you want to increase infection. When you need to slow infection, that tap can be turned off – at that point they close the schools.
Honestly, there is no way to stop CV19 now - herd immunity is our best chance of protecting the most vulnerable. In the meantime, we should do everything possible to stop those people getting sick.