Even that won't fix things. You could potentially eradicate the virus in the UK by doing so for 3 weeks, possibly longer. What then happens is you have a population still vulnerable. Once the lockdown ends and in comes someone from abroad, asymptomatic but infected? We go back to square one.
Sadly I have to agree with you both.I don't think we'll ever stop it completely as its in the wild now. Do what Auz and NZ did and it'll simply come back when you open the borders again no matter how careful you are. That's my biggest misgiving with the more draconian lockdown measures - permanent damage for a very short term gain. Most likely we'll have annual vaccinations similar to the flu jab, limited outbreaks on occasions similar to what happens with swine flu, MERS, SARS etc which will be contained locally, and in a year or two it'll be normal jogging.
The good news is I'm alright.