It depends on field and more importantly, country. I was the last person in my year (that I know of) at CMU to get a PhD, a whopping 9 years after we started. A friend had to re-enroll to get his 10.5 or 11 years in.

Meanwhile, I knew tons of people who got PhD's in CS in 4-5 years back in Australia. They typically did zero coursework or breadth stuff, and they were able to start dissertation work within a few months of the clock starting on their degree, without the undignified business of having to propose their thesis formally in public or even defend it in public.

The process of getting a PhD isn't order-of-magnitude different from field-to-field or place-to-place, but there's definitely a good factor of 2-3x between the most arduous process and the least (which does not mean that one degree is 2-3x better, of course).