Your comment gives the impression you've read none of this and only read meta-commentary. Or that you consider any person's story subjective and non-credible. In which case, what would you call a fact? The same standard would apply to any person.
(I wouldn't include the Isaacson bio, he regrettably focussed very little on Jobs' process.)
https://www.amazon.com/Becoming-Steve-Jobs-Evolution-Visiona...
Haven't read it, but I've heard there is a section of Creativity Inc where Ed Catmull talks about working with Steve and how they operated.
Finally, there's a site that occasionally surfaces here which had stories from the original Mac team. Folklore.org I think? That was a more raw period with more of a mix of immaturity in there.
But all of those have a variety of firsthand accounts.
The Pixar stuff in there was really interesting. Creativity Inc has been on my reading list because of that book.
In my opinion they really moved the needle on ubiquitous computing for the masses, and did a great job on their first attempt.