Value of PhD candidacy ("ABD")
For some departments, reaching the candidacy stage means you have earned a degree (often an MPhil, but it varies). If your department gives a degree when you reach candidacy, then it provides a nice break point to leave. Industry might be fooled by it, but PhD programs often know the difference between degrees that you were intending on getting and those that signify a departure from original plans. A degree might have some value Thor industry and PhD admissions, but in general, people are interested in what you have done and can do, and not in pieces of paper. If there is no degree, then reaching candidacy, doesn't really matter for industry or PhD admissions.

While it might not help for getting a job or another PhD, reaching candidacy might give you a sense of closure and/or accomplishment. The value of that is deeply personal, but a lot of people describe themselves as being ABD even if they have no intention of finishing. You need to weight the value of being ABD against the cost of getting there. Often reaching candidacy means taking qualifying exams. Quals can be really hard and if you are not 100% committed you could fail! which might be worse for your psyche. I am not sure anyone goes into quals thinking, I am going to pass and then quit. Did I mention quals are painful. I have since forgotten all my coursework scars, but my qualifying exam scar I think is with me for life.