To clarify, this is an adult biography on the life and work of picture book illustrator Garth Williams.
I grew up with Garth Williams art in my picture books as a child, then in my first chapter books - Stuart Little, Charlotte's Web, the Little House seres. He was the first illustrator name I actually attached to artwork, and could recognize his style, and fell into it. He may be the reason I went beyond loving art and studied illustration in art school, and wanted to become a picture book illustrator.
So this book was totally worth reading to me. However, I did find much of the writing tedious. When parts did flow it was a noticeable change. Numerous times in trying to be scholarly the book felt bogged down in the way details were presented. Also some details were given out of date order or repeated in, I suppose, in attempts to become more fluid, and avoid this date-driven data.
Hard to say with two authors whether changes occurred due to this collaboration or difficulty with this, the editing, or the sheer volume of research becoming unwieldy. I certainly could not take on this task.
I also found that in looking back at historical times, the voice was also set in the past. If this were due to quotes, I would totally accept and understand this. If this was written as a whole long ago, also understandable. But the copyright says 2016, so disappointed the language of the book feels dated.
Nevertheless, any illustrator would glean good information about how things worked back in the early days till recent times of Williams' career, and a good deal more about him personally if you loved his work and are curious to know him more, or surmise perhaps how one affected the other.