It's a poorly written brick but it does actually have the relevant algorithms.
To expand: a lot of the most important linear algebra algorithms basically don't _have_ a writeup besides in this book. You could read the BLAS or LAPACK source code, you can find random blog posts and presentations here and there, but this is pretty much the only complete reference for how to do linear algebra in a computationally efficient way. It is bad at doing that relative to how good descriptions of algorithms _can_ be, but afaik it's pretty much the only game in town.