While we are all bemoaning this for employment, note that in the US, in many cases, you've also given up your right to court for your credit card disagreements, disagreements with your insurance company, and disagreements with most major service providers where you had to sign a contract (though many telcos still provide an out for Small Claims court).
This is not just an employment thing, this is individual vs. group power dynamics across many aspects of commerce. As consumers or creators, if we provide work to a group (employment) or pay a group for service (a contract), that group is often working to push us into arbitration instead of allowing the courts to decide.
It's all very disappointing.