You have no idea just how big that IF is... do you?
Voluntary self isolation of international travelers just doesn't work. It has to be enforced.
Voluntary self-isolation works as well for new arrivees as it does for the rest of the population.
So we found out...the hard way and so shall you with out a doubt...
The vast majority of new cases were from international travelers, returning Australians and all the people they infected on the planes/ships and once they got here. We only started to see a reduction once we closed our borders and put repatriated Australians and those inflight at the time into forced and guarded hotel accommodation for 14 days...
Australia reacted much earlier, sure, and those measures at that time helped contain it. The UK did those measures as well, if you recall, but much later in the game. And once the spread got too far those measures became less important. Such that they were no longer required compared to what the general population was already doing.
As you yourself say: "the vast majority of new cases were from international travelers..." - that is simply not the case in the UK, and hasn't been for quite a while!
As exchemist has pointed out - only when each new case coming in has a significant impact is enforced quarantine useful, and that time is approaching. But while the UK incurs 5,000 new cases a day, incurring 5,001 in a day is of little importance to the situation.
I don' t need to create sensational headlines... you guys are doing that all on your own...
You are looking at stats, drawing your half-assed theories, asking sensationalist questions, and simply can't help yourself from pointing at things and going: "ooh, terrifying! Ah, that's terrible! Wow, that's shocking!" Recall that not too long ago you were asking if the UK economy will survive!
To approach a national quarantine against a virus like this in such a half hearted manner is why your stats are so terrifying..
In what way are the stats "terrifying", QQ? In what way is the approach of the UK "half hearted"? Or are you really just comparing to Australia and going "oh, look, the numbers are much worse, therefore their approach must be half hearted and their situation terrifying!"?
Post facts. Post well thought out opinion based upon those stats. Just stop with the hysterics, fear mongering, and sensationalism.