It depends. If a person has a chemical imbalance or a brain issue talk therapy won't do shit. Sometimes people need to be taught how to deal with their feelings as they were not taught as a child. Sometimes people need to be able to express their feelings and don't have other options.

Yes sometimes people's lives suck. If you grew up watching your father punch your mother every time he got mad, that's the only way you know to deal with anger. A therapist may introduce you to alternatives like going for a walk, taking a shower, how to express your feelings with blaming the other person("you should have dinner ready when I get home" vs "I'm hungry after a long day of work"). In those cases talk therapy may be useful.

If someone has schizophrenia or clinical depression that's different though. They need other options.