Tresidder is in some ways likeable and reasonable, and in other ways sort of a skinny-FIRE Robert Kiyosaki who is "retired" but still shills constantly in the direction of his $1,750 online course like he read The 4-hour work week.
Most of the book is criticism. On page one we get "Traditional retirement planning has failed." It all feels mostly like a sales tactic: His approach is the one that works!
He spends a lot of time criticizing Monte Carlo methods. His explanation of the approach in general is so bad it must be deliberately so. Unsavory rhetoric.
There is a reasonable argument buried in his hate for MC methods: He thinks they don't go far enough in considering more extreme possible futures, while their confidence intervals make them seem all-knowing when they're not. They generally won't model Social Security disappearing altogether, for example, but they'll still allocate 100% of probability, as if there's a 0% chance of these sorts of "extreme" futures.
So his solution is a sort of manual Monte Carlo, putting lots of weird things into (his, of course) calculators.
He also correctly, I think, focuses on the human reality of living just one life, not a probability distribution of lives, so what we really need is to eliminate extreme downside risk as much as possible.
How much of the retirement planning literature is just confusion about inflation? Possibly a lot, I think.
It turns out his solution is mostly from the skinny-FIRE school of thought: Spend less! Then there's the Robert Kiyosaki part: Cash flow! Real estate!
I object to telling people to become landlords like it's easy, good, and risk-free. The general idea of not dipping into your capital seems fine though. But now are we just back to the original methods he despises, only worse off because we're imagining the capital is safe (and even grows with inflation)? I think yes.
There are some good vibes about enjoying your life, and maybe his recommendation to consider a longevity annuity is reasonable, but for the most part this book is more an advertisement than a resource.