Before telling my opinion about the book, I'll say that I'm a platform engineer. Most of the time my job is to build in-house CI/CD pipelines, automations, platforms provided as libraries or the whole SDKs on which other developers in company are building products.
So... maybe... my opinion is biased towards this book, because for years I was working in organizations huge enough to have their own problems that can't be covered by general solutions outside. That's why in-house proprietary solutions are created most of the time - to cover problems others can't solve or it will require a huge effort to customize the solution to solve it. Which is sometimes more costly than creating one. But anyway...
This book is not for developers, in my opinion. I mean, not the "classic" ones. Too much content is circling around DSLs to describe business processes which then consumed by generic workflow engine. These DSLs are describing what process to trigger which is some sort of code e.g. Java (as in the book). Transient errors, timeouts, persistence, etc. are covered by the workflow engine and it is kinda magic and should help most of the time.
But I don't believe this is working as described in the book. Sure, there are some scenarios where it can and will work, but again, maybe I'm too biased. Once you become huge enough, you will face lots of challenges that can't be solved without building at least some sort of in-house solution to cover proprietary issues inside the organization. Be it technical or political or both.
I would say that this book is more useful for those who is closer to the business than developers. Like business analysts, for example. Or, I don't know, some sales person who want to automate some part of the job. They need it to be simple enough not to call developers in. But feature rich to really automate something.
I've got myself too wordy here. Yeah, so, in my opinion, this book wasn't for me for sure. I didn't understand the benefit of applying workflow engines whenever we could. Although I do understand the practical use cases for it, I can't say I see it in my day-to-day job. So this book is OK to see and hear how other people solve their problems, but no more than that.