Look, I read it and loved it 25 hyears ago.

Fred Brooks wrote that book when they were programming IBM operating systems in assembly language.

Times have really, really changed - do not pay attention to the messages of this book unless for historical fun.

The lessons in that book have broadly held true for nearly every single one of my employers throughout the entirety of my career.

Indeed a lot of things have changed. A worthwhile exercise is to read the book, contemplate how things have changed, and try to map lessons from the book onto modern technology and organizational practices. A LOT of the core principles are still relevant IMO, even if many of the implementation details are not.

Your comment and the OP both mention some things that are outdated about the book. What are those things?

Our field is full of vague, terrible opinions and useless advice. Arrogant people that think they're better than others.

That book isn't, it's built from humility and a rare bright light in this god forsaken field.

IMHO, Brooks's Law applies more today than ever.