Then why aren't other European countries taking the same attitude? Instead they are creating chaos at their borders by treating all UK visitors as non-EEC citizens?

Is it getting revenge on the UK for Brexit? I have spent over an hour getting through the border at Amsterdam, Madrid and Malaga recently. And that will only be worse later this year when I have to apply for a visa and be fingerprinted when the new regulations come in.

Why is that not also "a total mess"? And if other countries are willing to inflict a total mess on non-citizens and give an easy passage for their own citizens, then why does the UK not do the same irrespective of the queues it would create at the border desks?

Believe me, this will become a major topic once those new European visa/fingerprints regulations actually come in. British citzens going on holiday to Europe will spend hours getting through the European border - and when they get home they will see Europeans sailing through our e-gates alongside them.