I can give you my anecdotal perspective.
Out of the 18 in my cohort, two are doing reasonable postdocs (i.e. positions that aren't just treading water, but should actually lead to a reasonable career) and one who has been remarkably successful (success being a 'young investigator' grant - basically an R1 - and just recently another million+, within two years of PhD). The rest (including me) are doing ... other stuff.
Here are some traits of the successful PhD:
* Mother is professor in a related-ish field. Sister is also a PI of a gov't lab. Has been steeped in research and academia (especially the interpersonal aspects of this!) for decades. His success is 100% merited, but without question this has aided him tremendously.
* Reads papers constantly. I don't know anyone that's as familiar with the literature as he is, including all the faculty I've gotten to know. Has strong opinions about various labs, papers, and researchers, all of which are very well substantiated. TONS of 'soft' knowledge about how so-and-so got this or that funding, why such-and-such research is bunk, etc. If you don't think half the faculty in your doctoral program are trash, you're not being critical.
* Not a terribly great bench scientist. Definitely competent, but not remarkable. He knows it, though.
* Holds many unpopular opinions, and strategically focuses his research goals on the 'achievable'. In other words, he doesn't let being right get in the way of his career. Don't interpret this overly cynically; you can absolutely go against the flow in academia, but big claims require big evidence, and your time is limited. His research focus has shifted a lot depending on the landscape in front of him. I think this is commendable, as idealism in research is extremely fraught, even if some would criticize this. FWIW, he published a 'comment' in science that basically shits all over a garbage paper, which is more than most will do.
* 10 'real' publications since starting PhD in 2010, 7 as first author. By this I mean actual original research in a journal of repute, not reviews or bottom-tier trash. And this covers what are easily considered 3 different topics/fields.
* PhD advisor is Academy member, post-doc advisor is Academy member, institution is top-3 in field, arguably 1 or 2, etc.
The core takeaway is that you need to understand your field (in a very wide sense of the term) and direct your research productively according to that.
You certainly don't need all that to become a professor at Podunk-U, but I think that's a good archetype for a successful investigator. The other successful PhD (different cohort) I know has a very similar story; dad is a 'big dog' in an even more similar field as the son, similarly productive, similarly knowledgeable, etc. I feel pretty confident that this is what's needed for success at a major research university. Though, many unsuccessful faculty will be hired as well (through luck and, very often, nepotism), so YMMV.
If you really like to read papers in your free time, I think that's a very good sign. Even better if what you like best is to read between the lines and really be critical of the work. Very few people, even in doctoral programs, are like this. Know and respect your weaknesses, as well, and you could be great.