Thinking about the experiences of first year teachers.
Anecdotally, new teachers have terrible experiences with "student teaching." There are ample reasons for this.
I suggest that a new model must be introduced that better supports and aides new teachers. For instance, remove the "student teaching" requirement and replace it with a general period of observation and "assistanceship" that leaves the primary teacher in charge (which is what they want!) but permits the learning teacher to observe and reflect on teaching practices.
Then, provide new teachers with a scaffolded real teaching experience. For instance, integrate their first year teaching with their licensure. They may only be paid 50%, for instance, but they also have only one prep and teach only 1/2 a normal load of classes. This real experience in a supportive environment with the time needed to actually prepare lessons and reflect on their teaching would greatly improve the first year experience. I propose that this would increase teacher quality and retention.