It's not up to the courts. Congress passed a law, the Federal Arbitration Act, which explicitly instructs the courts to treat arbitration provisions at least as favorably as any other contract provision. In the absence of a conflicting Constitutional provision, the courts have no choice but to enforce the statute Congress passed.
Im a lawyer, you may be one too as we are a dime a dozen, but if not here is a dirty little secret...
The courts don't care what your litigation costs are, the only thing they care about is having as few cases on their docket as possible (i.e. They care about their own costs and their own workload).
Nobody is saying that arbitration shouldn't be available, or an option. What is being ragged on is the idea that a company should be entitled to put a mandatory binding arbitration clause into a contract that isn't negotiated, that in reality, a consumer has zero power to change.
The courts do, or buisinesses who lobbied congress for the mechanism do? Speculation, I don't actually know how this sausage got made, but I imagine it had a lot of grease from big companies.
The prevailing narrative is that the court system is somehow constantly overloaded, so everything from settling out of court to plea bargains to private arbitration are favored.
You don't need to couch this in conspiratorial terms: it's not "the prevailing narrative", courts ARE overburdened. The "somehow" is that they are underfunded and understaffed, because creating more judicial resources means spending more money and often raising taxes, which no one wants to do.
Everyone wants more judicial capacity, no one wants to pay for it.
The courts do prefer it, but from a legal perspective, as an adhesion contract with boiler point terms, the arbitration clause shouldn't have been enforceable.
It is definitely lower cost (and the vast majority of arbitration clauses end up allowing choice of arbitrator by plaintiff, or arbitrator is randomly selected with a couple chances to reject)