The sentence is worded a little confusingly, but my interpretation of it is that for certain companies, since Amazon is a competitor in the business domain of that company, AWS is a nonstarter even if it's product offerings are a better choice. Walmart is the canonical example.
You don't spend a percentage, you spend a fixed amount. $1.5 million is enough to live in a nice house, eat what you want, send your kids to nice schools, Aruba in the summer and Aspen in the winter, and still have enough to buy a very fast car. It's easier to focus on EV once you live this life.
In case you were unaware, the source code of the original is included along with the re-release in this repository, as stated in the first sentence of the readme.
There are certainly areas where idiomatic Rust needs to fight against the borrow checker. If that wasn't the case, things like `ouroborous` and `pin_project` wouldn't be as widely used as they are.