Objective-C message sends are ridiculously fast these days, like less than a handful of nanoseconds on average (1-2 on the fast path). There are ways of making it go even faster, but Apple has chosen to sully the language by taking away some of its dynamism instead :( It’s kind of sad to think about how much the original iPhone could do and how much code goes into the average app these days in comparison. You’d guess it was assets or something but no, if you look at major apps these days they have all sorts of framework dependencies with multi-megabyte binaries. It’s so sad to see…

(And Interface Builder files get compiled to a format that is then read out at runtime and deserializes the right things.)