Even if an application gets localised, it may do less formatting of localised messages than of non localised ones (think (debug) logging, textual protocol formatting, exception messages and the like)
I also expect that a large fraction of applications never gets localised (in-house tools, scientific software, etc).
In total, I think there are orders of magnitude more lines of message formatting code that do not get translated and likely never will be translated.
It appears modern language designers think it worthwhile to make life for that use case a bit easier.
(it is not that the code gets much shorter, but more that, for true translation, you have to move the format string into a resource, and load it from your code)
I also expect that a large fraction of applications never gets localised (in-house tools, scientific software, etc).
In total, I think there are orders of magnitude more lines of message formatting code that do not get translated and likely never will be translated.
It appears modern language designers think it worthwhile to make life for that use case a bit easier.
(it is not that the code gets much shorter, but more that, for true translation, you have to move the format string into a resource, and load it from your code)