then the solution is to have government, public, and industry, appointed boards paid for by fees on the companies who want to use mandatory arbitration
No, if the court system is broken then fix the court system. Class action is not to give the public relief it's to keep companies from taking 1$ from 10 million people when none of them would benefit from dealing with it. For slightly larger issues we already have small clams court which works for mid sized issues. And larger cases can go though the full court system.
To be clear, class action cases hurt firms far more than they help people, but that's their job. If we want to replace them then the government needs to step up and prosecute company's for this stuff.