Thanks for the correction on the new variant.
Re-reading, I see that my post could have been read to support closed borders. Actually, I am just amused that they have failed in their task. For decades, the rest of Europe has checked people In and Out but the Brits merely In. But, if you do not know who has left officially, you cannot know who has remained. Yet, so many people in this country (and the politicians) are very upset at the number of people who overstay their Visa - but they do not know who they all are! Further, I suggest, the knowledge that, once you get in, it is more difficult to be found because they do not know when you leave, has attracted some people to the UK
Whilst they may have pax lists from carriers and shipping companies, this is all second hand. So, I do not mind that they do not check departures, but they have not done what they said they would. Which seems to be the way of so many modern politicians.