A chargeback system is a protocol requiring centralized trust. A company will no doubt implement this.

Centralized trust is of course necessary. One could argue that it defeats the point of bitcoin. Yet that's not true, if you think of bitcoin as being a currency (rather than a "secure" currency, or any other label). If it's a currency, then a chargeback protocol is simply a company waiting to happen. And the company would necessarily have to be large, because it has to bear the cost of fraud. Luckily, PayPal has already done a lot of the homework necessary to pull off such an endeavor.

Lastly, it doesn't matter what normal people use. It matters what will become convenient for normal people to use. That's a subtle distinction, because it means as soon as infrastructure is built then people may start using it by default.