Philosophy encourages critical thinking

Self-helps are often repetitive copy-paste works from other books, but self-help can't copy-paste philosophy. Philosophy questions the subject to get a clearer answer instead of just touching the surface. They question the what, when, where, who, why, and how.

Philosophy can save you from accepting blindly what people might call "great" or "you need to buy this". It can save you from blind preaching too.