Content based on interviews of those that have done it?

I want to learn about something, from people who have done something, so I can then help other people do that thing and I’m looking for examples of others who have taken on such a project, so I can see what might be viable and how it might look. Can you help me?

I’d like to ask if you’ve you come across any content you could recommend where someone has taken on a project like this - to learn about a subject, niche or market by interviewing those that have been successful - and has then published the findings for the benefit of those starting out?

An obvious example for clarity, would be something like the books of Tim Ferris: Tools Of Titans, Tribe of Mentors etc. However, this is much too high level for me and the target audience. Meaning the author is too big, and the people he interviews are also too big/successful. I’m looking for some more relatable examples/models/formats (and interviewees), to help me figure out, what the options might be to approach such a project myself.

The 'something' subject matter is not that important, and it definitely doesn’t have to be in a book format, it could videos, podcasts or even just a blog post (the point is to see how other have approached this).

Basically it just needs to be content based on a series of interviews or relatable role models or case studies, preferably limited in scope, where the interviewee goes on to share what they have learnt/concluded for the benefit of others.

So your ongoing standard interview podcast or anything about Elon Musk or Jeff Bezos is not what i'm looking for.

Appreciated, thank you.