Obviously, giving up any rights, including bringing and participating in class actions, is not in employees’ favor. Moreover, your right to have your case decided by a jury of your peers can be very detrimental to your case. One can argue that a jury of your peers are more likely to understand the everyday toils of working people than former judges.
Moreover, the incentives for an arbitrator are problematic. A large corporation is likely to get sued many times while you are likely to bring a lawsuit a few times, if ever, in your life. The arbitrator only gets paid if the Parties mutually agree to use the arbitrator. Thus, they have an incentive to cater to big corporations so they can earn repeat business. They do not have the same incentive to cater to employees who are unlikely to come back.
Employees do not always have a choice. Few employees are in a place to turn down work merely to avoid signing an arbitration agreement. But if you have the opportunity to avoid signing an arbitration agreement or opting out of the arbitration program, it can be very helpful in a future case, as it may preserve your right to bring a case in Court, bring your case before a jury, and participate in class actions.