from what I understand, arbitration is a way to come up with a resolution if possible before taking case to court. If arbitrator decision doesn't seem just to employee then why don't they appeal for court? Who own the cost of court proceedings in such scenario, company or employee? But given the exorbitant legal fees its not is favor of employee to take this route.
Because you signed a contract to abide by the outcome of the arbitration proceedings (i.e., it's "binding"). If you appeal, the judge will toss it out and you'll have wasted your money.
This is not really obvious if you’re not from the US. In Poland (and I guess other continental Europe countries) you can appeal to a regular court. The possibility to appeal to court is considered one of the basic rights one has.
that should be illegal, it should be impossible to waive a basic right. this will affect poorer people much more, as they have less experience, money to invest into a good lawyer and job options. it's not a fair process.