It's a matter of trust and incentives. How can you trust a program curated by an entity with no accountability? A therapist has a personal stake in helping patients. An LLM provider does not.
Seeking help should not be so taboo as people are resorting to doing it alone at night while no one is looking. That is society loudly saying "if you slip off the golden path even a little your life is over". So many people resorting to LLMs for therapy is a symptom of a cultural problem, it's not a solution to a root issue.
I'll start with a direct response, because otherwise I suspect my answer may come across as too ... complex.
> How can I trust a therapist that has a financial incentive to keep me seeing them?
The direct response: I hope the commenter isn't fixated on this framing of the question, because I don't think it is a useful framing. [1] What is a better framing, then? I'm not going to give a simple answer. My answer is more like a process.
I suggest refining one's notion of trust to be "I trust Person A to do {X, Y, Z} because of what I know about them (their incentives, professional training, culture, etc)."
Shift one's focus and instead ask: "What aspects of my therapist are positives and/or lead me to trust their advice? What aspects are negative and/or lead me to not trust their advice?" Put this in writing and put some time into it.
One might also want to journal on "How will I know if therapy is helping? What are my goals?" By focusing on this, I think answers relating to "How much is my therapist helping?" will become easier to figure out.
[1] I think it is not useful because both because it is loaded and because it is overly specific. Instead, focus on figuring out what actions one should take. From here, the various factors can slot in naturally.
Over the last five years I've been in and out of therapy and 2/3 of my therapists have "graduated me" at some point in time, stating that their practice didn't see permanent therapy as a good solution. I don't think all therapists view it this way.
Seeking help should not be so taboo as people are resorting to doing it alone at night while no one is looking. That is society loudly saying "if you slip off the golden path even a little your life is over". So many people resorting to LLMs for therapy is a symptom of a cultural problem, it's not a solution to a root issue.