I think how well therapy can work vastly depends on your "issue". Like, you just want to talk to someone honestly because you're just dealing with basic stress, depression over a single event (ex. loved one died recently), a single trauma/mental illness? I think that's probably more "fixable" than, say, someone who has multiple issues that aren't going to be magically fixed by just discussing them and "changing their view" or whatever (whether it be financial problems, living with abusive relatives, multiple comorbid mental health issues, chronic pain, whatever).
It also doesn't help that a lot of therapists will flat out talk about their patients to others without there being a need. They're supposedly only meant to if you're an immediate danger to yourself or others, but the shrink I had and my sister had a couple times as kids constantly told out parents what we discussed, which let to further abuse and isolation. I realized pretty quickly she was no help / actively harmful (at best she offered platitudes) and just flat out started lying saying I was fine and nothing was wrong and she seemingly just instantly believed me (mind you, I was fifteen and probably not very convincing).