Thank you Gadolhadorah for providing some of the important takeaways from this terrific discussion.
Let me add one additional (imperfect) suggestion not previously mentioned. Many people pointed out the near-tenure-like status rebbeim have, where it’s very difficult to fire them. Even if we keep that, perhaps we should have a probationary period during which a rebbi is initially evaluated for “tenure”. That is, perhaps it should be made explicit that for the first X years, a teacher will be carefully observed and at the end of that period will be evaluated for a longer-term job. At that point in time, maybe roughly 50%, or 90%, or 30% of rebbeim will become “tenured”.
This period will likely motivate rebbeim during those first few years to be excellent, look for feedback and training, improve, and become excellent teachers. With proper guidance this will be helpful even for the great rebbeim. Meanwhile, rebbeim that could be good or bad will be motivated to become good, and hopelessly bad rebbeim will know full-well from day 1, and through regular feedback, that there is a considerable chance that they won’t be kept around, and might allow them to plan accordingly. In many universities, professors who do not get tenure are given a year or so to find another job. This will relieve some of the stress that some rebbeim would certainly endure in being unemployed, and would hopefully also end the horrible practice where schools might notify teachers in the summer (!) that they won’t have a job in the fall.