At the time, the conventional wisdom was: Don't get a graduate degree unless somebody else is paying for it, or you are in a job that guarantees a salary bump for doing it. I don't think that's changed.

At least in my field, physics, lack of sufficient funding meant you didn't get students.

This whole business wasn't risk free. There were students who dropped out because their prof lost funding. In my view, the risk of not finishing at all is a bigger cost of graduate education than the pay scale.

You will not get paid well as a PhD student, but there is no massive amount of debt involved either (and again, whether there are opportunity costs is a separate topic).

I did hear of a German uni that accepts people for PhD programs without an undergraduate degree, but iirc you need like 4 or more publications. But that seems like an exception to everywhere else.

You absolutely can get a paid for ba and ma in the US. It isn't easy, but thousands do so.

Moreover a good high school mentor will help you navigate to good financial aid (I have friends who came from the lower middle class who did not pay a penny for their Yale or Harvard or Cornell undergraduate degrees). They did pay for books though...

This didn't used to be the case, so, yes it is true to say it is unrelated to the PhD programs if you set aside what it takes for people to enter them in the first place and the decisions that have to be made by all actors (of which only the self has control over).

>Moreover a good high school mentor will help you navigate to good financial aid (I have friends who came from the lower middle class who did not pay a penny for their Yale or Harvard or Cornell undergraduate degrees).

Yeah sure, my sister got a full ride for undergrad and for her masters and my cousin got a full ride for undergrad, but for every person like them, there are many more that even leveraging such knowledge of opportunities and trying to pursue them in earnest, doesn't net them opportunities.