All of those apply to physical illnesses: they usually mean you should see a doctor, doctors are in short supply and often inaccessible for financial reasons, oftentimes there is a proximate cause that a healthy lifestyle can get rid of, and being told you have a "physical illness" isn't specific enough to be helpful. All of these things are true, but it doesn't make "physical illness" a non-true or useless idea.
Indeed, and just saying “physical illness” is pretty meaningless. Beyond that though, there’s sadly a lot more empirical data and practices behind medicine than psychology/psychiatry. You go to a doctor, you can get a diagnosis and effective treatment for many conditions in relatively short order. Therapy is generally the start of a years-long process. Psychiatry is more guesswork than science. That’s not to say they aren’t extremely helpful for many people, but I don’t see the two fields as being equivalent.
