^ Or to put off the real world for a couple more years.

If you have a trust fund, do it.

If you are gaming the system, do it.

If you are retired, do it.

otherwise, what is the point...I have a pain in my side doc, can you fix it?

Can be less time than 6 years, depending on where in the world.

My PhD took 3.5 years at U of Tokyo. I had full scholarship and housing allowance (normal for PhD I think to have a paid study for all or some of the process). I also worked during my studies, except for about 6 months at the end when i focused completely on writing.

Here in Japan professors are required to have PhD, and about 90% also have a license and a practice (unless a historian). There are no professors who do not know how to build and none of the anti-education silliness that North Americans have.

That said, there are times I wonder if it was the best choice. I teach at a good university, have run studio with Sejima and Maki, and learned quite a lot about the practice of architecture that I would not have without the position at university. Far from being an ivory tower University is extremely connected to industry and research is required to be cutting edge, both theory and practice. Lacking a PhD I would not have access to any of that, so in hind sight I do think it worked out. In the past 5 years I have been learning about IoT, CNC, 3d printing, digital fabrication, and business planning. These are useful things that influence our office practice. Basically PhD is a commitment to continuing education at a high level. The challenge is to make use of it in a meaningful way. I hear of many  people who do not, but it is maybe partially luck, partially intention that makes the difference.

For what it is worth I came to Tokyo from London (born on Canadian prairie, small city) and knew I was going to stay here for awhile, so I applied to do PhD partially as a strategy for meeting the community I was going to work in and to give me a kind of position that I could build on in the future. That worked out. The partners in our office were all PhD students with me. One dropped out to start a real-estate fund, but the rest of us completed the degree. My research was on urban planning. The topic was entirely personal interest. I was curious  about it.

Having a PhD from the school I went to meant I could teach in Japan at a high level, and it also has a continuing impact on our clients that is undeniable. I will never be treated the same as a Japanese, but this gets us a bit further than if we just started an office without that background.

I did not have a trust fund. I was not gaming the system, no idea what that means, seems a good way to get into trouble. I wanted to learn something so I did, and made sure that it was meaningful for me in other ways too. Making that happen requires some self awareness and awareness of the world, perhaps, as well. If you cannot see any way out at the end of the process then it is not a good choice. 

One thing to be aware of, just as architecture is insanely competitive as a business, teaching is just the same. Jobs are few and far between and you have to be very active to get a foot in the door. It is not a pathway to a simple life. Also, while you study your income will be low, and it takes time to catch up when you get through the other side. It took me almost a decade to catch up to where I was when I started. My income is higher than it was though, and definitely higher than if I had just gone into an office. It is a bit like starting a business. If you work very hard you get somewhere in the end, but there is no guarantee. Oddly, PhD study has turned out to have more in common with entrepreneur mindset than I would have imagined at the outset. If you want to be a cog in the wheels of a big company it is not the way to do it.

In UK, PhDs are 3 years and often you can get funding.  In EU, PhD students are generally employed so fees with some funding is available.