It looks incredibly basic and difficult to incorporate into prep or play. It seems to be for people without experience.
Berin Kinsman has a nice set of books on gamemastering. He does have a bit of a minimalist writing style. The books have some good advice that isn't commonly discussed.
Robin Law's gamemastering book is a pretty good starting point.
The Alexandian is also good, but I have some style disagreements with him.
The old WEG starwars guide is very good for the basics.
Cthulhu d20 has a pretty good section on presenting a more thrilling game and horror.
Overall there is not a whole lot of great advice in the hobby. Most of it is the same bland or unactionable advice.
5e isn't just needlessly complex, it is an unreferencable mess that has very poor general rules with lots of exceptions and poor standardization. The rules for traveling are so misplaced that most players don't know they exist, not that it's possible to find them when needed. And when there are general rules, they tend to be unfun. Stuff like crafting has no depth in 5e, it's just time + gold = item. It might "work", but it's just bookkeeping there is no hidden fun.
For fantasy, I prefer Hackmaster 5e, because it keeps the complexity and detail without dumping special case rules onto players. It's not perfect, but it's way more engaging and characters feel way more interesting. WFRP 4e is also nice, but not as deep (it does suffer from rules being scattered everywhere). I'll likely end up playing OSE ot some point.