What you call "social proof" is really nothing more than your "reputation", whether that is online or within a certain industry, or just basic PR for name recognition.

As far as writing a book is concerned, if you are looking to get a deal with a major publisher, forget it, you are NOT going to get published outside of doing it yourself via self-publishing, not without a massive "reputation" in your area of expertise anyway. The reason the NYTimes doesn't list self-published authors is because it's a "closed list" designed to only promote the publishers who pay it the most money. If you paid the NYTimes the kind of money these old school publishers do, you'd get listed too. Self-publishing is a great way to build a reputation and get your thoughts out in front of an audience.

Building a reputation doesn't happen overnight. It also takes TIME. Lots of time.

Also, if you wouldn't hire yourself, you're maybe in the wrong business. Reputations are built by people who know what they are doing. If you don't know what you're doing, building a reputation is bad idea.