If I (completely hypothetically) got a PhD in pure math with a minor in philosophy, what would be my chances of getting an academic job (research most preferably)? I live in Northern Europe.
This varies enormously between people. I've known some students where it seemed clear that they had a 99% chance of getting a job at a research university (with the most likely failure mode being some major personal difficulty, such as an accident or illness). I've known other students who I thought had little or no chance. Most have been in between, of course, with only a few outliers.
There's little value in statistics over large groups, since they can give a terribly misleading impression for any given individual. (Different departments or advisors can lead to radically different outcomes, and averaging over them is pointless if you aren't choosing at random.) Instead, I'd recommend doing two things:
Talk with faculty you know to see what they think of your chances.
Look at placement records for particular graduate programs or advisors you are interested in. There will still be a wide range of outcomes, so you can't learn anything definitive from this, but it will at least give you an idea of the range of plausible outcomes. You can usually find lists of former students on people's web pages or the math genealogy site, and then you can try looking these students up. (If you can't find a former student online, then this person is probably not in academia.)