Many people come to therapy with a harsh inner voice that judges them more strictly than they'd ever judge anyone else. Self-esteem work isn't about repeating affirmations until they stick — it's about understanding where that internal critic came from, and whose voice it originally was.
Often this voice formed in response to real relationships and real expectations, early in life. Once you can see it as something that was learned — rather than as the plain truth about who you are — it starts to lose some of its authority.
This is quieter, more gradual work than a confidence-building programme, but it tends to produce a steadier sense of self underneath.