It doesn't say you can't sue them, it just says you must use binding arbitration when you do, which means you can't have an official judge or jury... a single neutral third-party (usually a lawyer or retired judge) becomes both the judge and jury, and their decision is final.
I think the incentive for them is that arbitration cases are usually harder for consumers to win, and/or the case gets resolved much more quickly than going through the traditional court system. I would imagine things like huge punitive damages or class-action suits are a lot harder (or impossible) to have as well.
https://www.reuters.com/legal/government/amazon-reinstates-b...