There are kinds of bugs that Swift can provably catch that Objective-C can’t.
There are bits of safety that Swift can ensure without needing to do additional boundary checks or something else, leading to faster/smaller code.
Perhaps biggest of all Swift doesn’t need a runtime like Obj-C. Apple has done an amazing job tuning it, but a direct function call is always going to be faster than message passing.
There are kinds of bugs that Swift can provably catch that Objective-C can’t.
There are bits of safety that Swift can ensure without needing to do additional boundary checks or something else, leading to faster/smaller code.
Perhaps biggest of all Swift doesn’t need a runtime like Obj-C. Apple has done an amazing job tuning it, but a direct function call is always going to be faster than message passing.