An academic Great Gatsby Curve – How much academic success is inherited?

Even if we pretend nepotism doesn't exists, academia is still not a strict meritocracy. In addition to merit, at least two factors play an important role in success, which having a good mentor helps a lot.

1) Tacit knowledge. In many fields, there are important information only accessible from having a mentor like heuristics, insider information, in-lab techniques etc.

2) Investment opportunities. A good adviser is often good at spotting opportunities for their students. It's also common for an academic adviser to share their most valuable opportunities with their students.

It's clear to me that the ideal of meritocracy (talent and hard work leads to success) does not hold in academia, and maybe not anywhere. Having a good mentor gives you extremely valuable information that contribute to success. On the other hand, I am not sure this can be fixed or even needs fixing. I think it's healthy for academics to be partially siloed, so that they can develop their unique approaches and maintain a healthy diversity for the field.