You can do that too. You can show up, represent yourself and pay a few hundred dollar court fee, while the big company has to waste hundreds of thousands of dollars to defend themselves from you. You'll probably lose the case if you don't have a lawyer, but in a place like the US, you don't have to pay the other side's legal fees unless the case is frivolous (which it won't be).

>The law matters very little when enforcing it in court often means a multiyear lawsuit against an opponent which employs an army of attorneys, has effectively unlimited amounts of money, will likely cost you ruinious sums of money, and for an outcome that's far from guaranteed.

Or when you can't even enforce anything in court as you've already given up your right to spend all your money suing, as binding arbitration is the required and only mechanism to "resolve disputes." To make it extra fair, the corporation pays the arbitration firm for their "objective" decisions and not you.

What could go wrong?

The judiciary is a branch of government. But more crucially, some countries have better consumer protection agencies, eliminating the need for people to go through costly court battles for common sense stuff.