That’s a very good point, you’re quite right. However all three of those are relatively very small population centres with very easily controlled borders. Britain does have the advantage of being an island, but it has a large rural hinterland that the virus can ‘hide out’ in, and many dense population centres without borders, so it’s a completely different environment.

Take London. We could introduce a system of tracking and isolation within the M25, and that might work to lock down community transmission within the London population, but millions of people flow into and out of London each week so it would be completely pointless and ineffective. Meanwhile that level of tracking and isolation simply can’t work across the whole British isles. It’s administratively and logistically impractical.