There are way more PhD's then there are research positions, so we are very far from the deficit you fear.
Nonsense. Look at how many job openings there are for PhDs - people can't hire them fast enough. I was in a call the other day saying how hard it is to even find PhDs to interview, let alone get them to accept your offer.
For A, PhDs ought never be short of work. They were likely good students, they also spent 3-5 years looking at the state of the art in their field. Something should've rubbed off along the way. So a PhD is usually a good signal (but many smart people decide not to do PhDs, as well).
For B - the supply of places which will pay you to do actual research rather than company-specific goal stuff is much reduced compared to the supply of PhDs. This is why you'll find plenty of PhDs at Google doing software engineering - sure they're PhDs and they're smart, but they're likely not still publishing much. Whereas MSR/IBM research groups do publish (and in many ways act like a university).
For C - the chances of getting to tenure-track professorship are low, and when people say there aren't enough jobs for PhDs this is generally what they mean: there aren't enough academic jobs. The usual process is to become a postdoc and then to become junior faculty - a professor, but not tenured. Then you must seek promotion into a tenured role. Sometimes people skip steps, but this is the path people I've talked to have taken. Each stage is competitive: you have to convince a professor to take you on as a postdoc, then you must convince hiring committees you should become faculty and that you have the potential to become tenured. All the while, you must deliver enough research output to back that up.
At each of those stages, there's a relatively high attrition rate, and this is amongst people who obtained PhDs.
Now, there are hot topics that may see something around this amount of growth for a while, but many don’t. For example, in biology, genetics and biochemistry may somewhat have that growth rate, but if you’re in any other subfield such as ethology, forget it. If you’re a historian, did research on some ‘obscure’ language such as Middle English, or are working in some corner of mathematics that doesn’t have direct applications, you can forget it, too. If anything, the number of tenureships in those fields is shrinking.
Of course, many tenured professors have a lot more graduating students during their career. In medicine, one a year isn’t uncommon. That would require a field that grows by over 12% each year.
The deceptive thing about this is that, as a phD student, you don’t see those 30 competitors. You’ll only see maybe eight to ten. Some of them graduated a few years before you, others will start after you graduated.
Which means that having more PhD students means you can explore more of your own ideas by assigning them to it. It also means more teaching assistants and so on for your course. So the chances you will take and graduate one at a time are very low. Also, you know some fraction won't make it, so you need to account for that too.
It's not uncommon to see PhDs after five to seven years in industry in the C-suite. That is less common for MBAs, from my view.
I also sit on a graduate admissions committee, and it's hard to find good students.
We have work enough for easily 10x as many STEM students in the US.
> it's hard to find good students
Maybe because you provide such a bad deal for the majority of your students?