Swift is far more readable and a bit more concise than objective c, that makes it more maintainable. The bigger win is of course optionals, which, (if you embrace them properly), can mean your app will never have a dangling pointer or runtime crash from a nil pointer.

I spent nearly 20 years writing object oriented C and Objective C apps for personal computers and phones, and dangling pointer crashes were the biggest possible sinkhole of time, and worse degradation of product quality.

I can't imagine ever going back to objective c.