I personally feel that we're in a much better position now than we were in the few weeks before lockdown. If you recall, they would only test people if they had been abroad, yet we now have been told that Covid19 came to the UK on 1300 different occasions, from Europe, so as many suspected, the actual cases were much higher at this point, we just didn't know! Someone on MN said before lockdown there has been estimated as 100,000 daily cases, though in unsure if that's true and if that's UK or Worldwide.
This time, anyone can get tested, so we can keep a much clearer picture on local figures and act quickly now the testing systems are in place.
Add into this the vaccine developments and the newly discovered treatment for worse cases, we're in a position we had hoped for coming out of lockdown.
I think that many people like myself and many of you will be cautious, we won't head straight into packed pubs or mix closely and so the government and their scientists have probably used data from pubs to work out how much % of people will do this and how many % of these people may have Covid when they do and they will consider if those numbers are manageable. Its not great because we wnat numbers DOWN but at this point, new cases may be offset by an even lower community transmission and care homes more under control too. I hope!
Summer will help keep cases low, we can have friends for Bbqs and meet outside which is what most people do in the summer. By September when the kids are due to return, the cases should hopefully be low enough to really stamp it out, possibly died out before then.
Disclaimer: Not a scientist, just applying my own logic.