My brother treats people who have COVID-19 and he says it's not affecting just the elderly, it's going to leave long lasting or permanent damage in severe cases, resources are almost down to where they need to start making triage decisions and this is with strong "flatten the curve" measures. Generally speaking, only a few got it so far and virtually nobody is immune, so not doing anything is just accepting that the load on the hospitals will be several times what they can bear and that will make the mortality shoot through the roof. The people need treatment, whether you know the name of the virus or not. If the UK wants to be the control group after all, well, sucks for the people who won't have a say in it.