The idea of this book is that if we want to make marginal improvements (2x), we can tweak things - increase the time invested a little bit, increase efficiency a little bit, improve sales a little bit, improve the product a little bit. If we want 10x, then "improve a little bit" won't work for sure.
Their prescription is to simplify - stop doing 80% of the things we're not uniquely good at and make incremental improvements over the best alternative (not over the previous state). Don't create a 10% better product than we were creating before, but create a 10% better product than the best other product in the category.
And to do that, you already need to go into niche markets and improve it that way - combining multiple unique capabilities, which can do 10x the output - by avoiding anything we're not the best at.
It's a business-style book, but I'm a fan of Sullivan and Hardy is a great writer (which is why it's good that they teamed up to write the book). I also liked Who Not How, but this is even better.
This is part of my philosophy and what I always explain to people. "Cryptocurrencies - Hack your way to a better life" is not just a better crypto book, that would be a very hard sell. It is so unique, that it has no competition - I write about things that no one writes about at all. That means you cannot compare it to other books. I teach how to live a "cypherpunk"/bitcoin/"crypto" lifestyle. That also means I recommend other books for various aspects that are not unique to what I create. This, I believe, is the best way to remove any issues with a competition - be in an area where there's no competition.