As for how it helps...
I guess that really comes down to whether you like talking to them. I do. It usually makes me feel lighter and happier to talk to a patient, empathic person who is not otherwise connected to my life or the people in it. Even despite the copious BS involved, I like the feeling of being heard and having dedicated time to figure out the things I find confusing, upsetting or otherwise difficult in my life. I also usually appreciate the therapist’s observations. Even when I think she’s off, it gives me a chance to clarify and I like that. Plus I appreciate her supportive and encouraging presence.
Even when we’re talking about stuff that makes me feel awful, there’s usually a part of me that feels better for having said it.
FWIW I don’t felt the same way when I find a therapist dumb or boring. The person has to be somewhat astute and have a sense of humour.
I think it helps? In many ways I’m a better and stronger person than I was before I started therapy and I credit therapy for at least some of that change. But even if I’m just deluding myself and I’m no better, which is possible, it makes me happy to feel that someone is with me, on my side for that hour as I try to sort it all out.