[tomcam]

I disagree a little. While publishing a book is almost never a good financial decision unto itself, it can be a good way to “diversify“ by adding to your professional reputation if you lose your FAANG job. Should OP get laid off and is later being evaluated with roughly similar rivals in the job market, having the book authorship as a tiebreaker is probably a good thing.

[bdcravens]

Ditto for speaking at conferences, contributing to open source, etc. However the author is talking about building additional income streams, not firming up the foundation for a single primary one.

[ghaff]

Put another way, building a "brand" is often a good investment (and can be interesting) as a way to build on an existing income stream but it doesn't easily/reliably translate into a lucrative career as an independent consultant.