I think one reason is because, these days, psychosis is most often considered a biological/physical condition that should primarily be treated medically (and there are effective medications). Another one is that psychoanalytic therapy can sometimes generate a lot of confusion and turmoil which, in combination with active psychotic states, might make the condition worse. And many people in the mental health field also believe that psychoanalytic therapy may not be useful at all if the perception of reality is not sufficiently intact in a client.

There was this psychiatrist guy called Hyman Spotnitz who ventured into treated psychotic illness in the mid/late 20th century purely with a form of analytic therapy that he developed. This is his seminal work on it:
https://www.amazon.com/Modern-Psycho.../dp/0970392362

In the book, it is described that the original Freudians did not believe that conditions like schizophrenia could be treated with psychoanalysis because they thought people with psychotic conditions do not develop an object transference, which was believed crucial for successful analysis. Spotnitz describes an alternative in the book.

My first therapist (a psychoanalyst) was very strongly influenced by Spotnitz's work. It wasn't relevant to my therapy so can't share personal stories but there are still people who believe in it.