I think to some extent it depends on the language. In the article they talk about Swift's implementation, which by default does the slow, fancy thing (but makes it easy to do the dumb, fast thing). String manipulation in Swift is almost certainly going to be used for a GUI for end users of many possible languages / locales, so it makes sense to spend the extra cycles to get the fancy version by default. If it isn't the default then you'll end up with half the apps on the App Store displaying broken text on line breaks, ellipses, wrapping, etc. on their hand-rolled UI stack.