Now the the UK passport is no longer recognised as a document that allows freedom of movement across 28 countries

Just to head off Nigel, that is not what the passport does or did. As far as the countries of Europe are concerned, the UK passport has not changed significantly since before the EU existed, and for countries outside the EU it is entirely unchanged.

You can travel as freely to the countries now (leaving the covid-19 stuff aside) as you could while we were in the EU, apart from joining a different queue at the border, and you many need something like the US ESTA eventually.

"Freedom of movement" has always been, in my view, a poor choice of words. It is more like "freedom of employment" really. That has been lost, but the ability to visit has not.