I'm with @MonsterEnvy , the vast majority of monsters follow the DMG guidelines, particularly after the MM. The CR system isn't broken, but the encounter building system is bit out of the expectations of most people (or at least most people on this website).Considering the official CR system is famously…laughably busted, I’d go with Micah’s assessment over the rulebook. The monster books don’t even follow the DMG’s guidelines. CR really is a joke.
The bigger problem is many people don't understand how to apply the CR guidelines or what the encounter guidelines are really saying.