I don't think that's the point of the book. There is enormous benefit that can be gleaned from building a "workable" implementation from first principles, even if it's not actually production "workable". These types of books are rare and very challenging to write, will definitely be taking a look.
Yes, screw the people who allocate capital and make purchasing decisions. Who would ever need their favor to found a successful enterprise software company...
What I like about this library over Material UI is the complete separation of styling, I really don't like how styles are written and passed as an object in Material UI and the requirement of getting muiTheme() from context for most components is just maddening, especially painful during testing. But what I'd really like to see from a material ui library is one that uses ITCSS for styling, check out the grommet UI library which is just an amazing library to work with, and the ITCSS makes editing and customising components a breeze.