Cannot comment on swift but I presume training data for it might be less avaialble online. Whereas Python, what I use and in my anecdotal experience, it can produce quite decent code, and some sparks of brilliance here and there. But I use it for boilerplate code I find boring, not the core stuff. I would say as time progresses and these models get more data it may help with Swift too (though this issue may take a while cause I remember a convo with another person online who said the swift code GPT3.5 produced was bad, referencing libraries that did not exist.)