I think the "one thing that's not like the others" in the article are the crazy-high rankings of Britain's top schools. Universities are a bit of a self-perpetuating reputation scheme, and the UK has been punching well above its weight in that department. Having worked with all Europeans, I can't say that I found the British to be skill or preparation outliers. Maybe just a little above the mean? Speaking English nat…
The problem(in general) with University rankings is that the ranking is done almost entirely on the number of publications.....in English. So it's no wonder that British universities take a lot of the top spots. I've had these conversations many many many times with people - it's not like the Universities of Warsaw or Milan or Prague are not as good as Oxford - but that's not what you're going to see in rankings because a lot of research doesn't get published in English, so somehow it doesn't "count".
As a completely separate point - British universities got absolutely decimated by Brexit in ways that are not immediately apparent, but I work with couple professors at Russel Group universities and they all say the same thing - the number of PhD and research positions applicants from the EU has gone from hundreds a year to literally a handful a year. Some of those were replaced by British applicants or non-EU applicants, but the number of people who want to be researchers in Britan and further the scientific fields has dropped drastically.