Should I go for a PhD in Oxford University? I recently got accepted into a PhD program at the University of Oxford after passing many admission stages including a very rigorous interview. 

I've always been a good academic, and I do have a promising startup making around 10,000$ a month. I've got funding for my PhD as well; money is not the problem. 

However, after thinking a lot of about it, I hate academia, and I do never want to be a researcher. I do not want to be a tenured professor or be in an academic environment in any way, nor I want to make future publications.

If I go for a PhD, I do know what I am signing up for; I searched for months on what a PhD sounds like. The countless hours of work, the supervision, the isolation, thesis work, wanting to quit and everything else.

I am passionate about my PhD topic, and I think I can contribute to that field using projects and research.

If I go there, it would be something I am deeply passionate about.
Furthermore, the main reason why I want to go there is that it is 'Oxford' and I get a permanent legacy being an Oxbridge graduate, as well as holding a doctorate degree for the rest of my life.

My parents are supportive and aren't pushing me to do it. They told me to do what I want.

Academia took over my life since I was 18 and wasting another 4-years for that means I finish 27 where most of my 20s would be wasted for academia.

I've asked my academic advisor, and he told me rejecting an offer from Oxford might be a mistake I would regret for the rest of my life.

Should I go for PhD in Oxford or not? I have a non-ending dilemma.
If you will think of time spent on the PhD as time wasted, don't do it.

However, in considering the pros and cons, do remember that PhD students who are having problems are much more visible than the ones who are enjoying the experience. 

Supervision should be a benefit, not a downside. I remember some very interesting conversations with my academic advisor.

People working excessive hours, other than for short periods during emergencies, are less productive than those who are getting enough sleep, exercise, and social life. 

If you experience isolation, you are doing it wrong. A PhD is a time to network with other researchers in your chosen field, including but not limited to fellow graduate students.

Writing your thesis may be the one time in your life in which you can write about your research area without limiting yourself to a few pages. Why would "thesis work" be a negative?