Being a UK PhD holder, a sentence stood out out to me was a commentary/comparison between UK and US PhDs: "This was a three year UK PhD, rather than a brutal six-or-more year US PhD."
My cousin has a US PhD and judging from what he tells me. It is a lot more rigorous than UK PhDs.
The US PhD is usually 4-5 years after a 4 year bachelors (8-9 years). It is a little bit longer with more graduate-level coursework.
That said, the US bachelors starts at age 17 while a UK bachelors starts after 2 years of A-levels. So in terms of length it’s a wash.
AIUI you can do Highers (equivalent to GCSE, at 16) and enter Uni then with sufficiently high grades (aged 16/17). Or, stay on for one more year to do Advanced Higher (most common). Uni courses can then be 4 or occasionally 3 years. Don't quote me!