Is Atkins enough for Chemistry Olympiads?

Atkins' Chemical Principles: The Quest For Insight is a textbook commonly mentioned in the Chemistry Olympiad community, as it is a well-written textbook that introduces all of the necessary fundamentals. The theoretical knowledge from Chemical Principles is enough for 90% of Chemistry Olympiads. The remaining 10% that isn't covered is primarily organic chemistry, inorganic reactions, and common advanced topics (MCB, CFT, spectroscopy, Slater's Rules, etc.)