On a proportionate basis, tenured faculty has declined significantly: from 46% to 22% in the USA since 1975.[1] So, what was traditionally a 50/50 shot at tenure, Now it is a 80/20 long-shot. At the margin, tenured track positions are actually even rarer. Recall, of the 22% most of them are not recent hires. So, you're odds may be as low as 9/10 against you getting a tenure job...assuming you got any "faculty job" at all. Since the latter is also decreasingly likely, given a supply glut/relatively, the odds of getting an academic job that is also a tenure job are lower yet.

[1] This data is cited above.

50:50 would imply that 1 in 2 PhDs would get tenure; the odds were never that good.

One thing I can't understand is why are people not researching this kind of stuff beforehand? By the time you're doing a PhD you're in your mid to late 20's right? You should've been thinking about your marketable skills since you turned 20. You can't just do whatever you like and expect the world to throw jobs at you.