[seanhunter]

A PhD will make close to zero difference to the quality of job you get, so if you're thinking that an MSc will get you a boring job but a PhD would get you an interesting job that's absolutely not the case. I speak as someone who has had a long and fulfilling career in software engineering in spite of having a music degree, and knowing people with strong quantitative PhDs doing very boring work. (I would say they aren't "stuck" other than in their own perception however). It's on you to find yourself interesting work though - PhD or no, it's not going to land in your lap.

Secondly, it's definitely not the case that if you don't get a PhD now you'll never get one, however in all likelihood it will be much harder later on. In my experience, people's responsibilities and commitments (personal and work-wise) grow constantly and it only gets more and more difficult to find time for things in future.

It sounds like 9 months doesn't give you a PhD, 9 months gives you potentially the opportunity of a PhD. So it's a theoretical minimum and when you're looking at this, you should calculate on the PhD take longer. Be wary of sunk cost. Having invested time in getting an MSc, it's easy to think "9 months isn't that long given how much I've done so far" without thinking through whether the goal is worth achieving in itself.

tl;dr: Get a PhD because you want a PhD. Probably don't get a PhD thinking it will make some sort of difference to your job prospects.