I know someone who was in a PhD program for 10 years in Europe, without graduating. After year 6, it got very difficult for the university to legally employ him, and after year 9, it was simply impossible and he lived on his savings, but was still allowed to use his old office.

European PhD programs generally assume you already have a Masters in the subject so they skip most of the grad level courses and they typically don't do things like rotations either. You have a lab and some project to start on day 1. It's still overall faster to finish in Europe but the difference isn't as extreme as it sounds, assuming you do go for the Masters first.

In the UK it’s 4 years but you stop getting paid after 3 and a half.