I think something that is partly to blame is the expansive licensure scheme, and how those licenses have become a monopolistic edge to protect and expand. Many professions have required a license, and it is the responsibility of the organization that issue those license to protect an expand their authority, preventing competition, and pushing up prices higher. The license requirement creates a perpetuating lobby, whi…
A real estate license mostly teaches what you need to know about the laws around real estate transactions. It's pretty easy to get. Take the courses, pass the test, and you're in, there's no restricted access. You can set up your own brokerage and everything. But if you want your brokerage to have access to the MLS system, you have to join the Realtor organization. That's where the monopolistic behavior creeps in.
Also - whether MLS members must also be Realtors is a rule of the MLS and not a universal requirement. The NAR, nor MLSs, do not set commissions. In fact, much of the MLS rule changes in recent years that I've observed have been about making sure non-Realtor licensees have market access. It's right there in our paperwork that I show clients where we ask permission so that the seller knows who will be entering their home.