John Sundell wrote a comprehensive article that shows briefly how Swift has evolved from its conception to its current state today and wishes for the future.
However, perhaps the biggest impact that Swift has had on the Apple developer community isn’t so much a technical one — but rather a cultural one. While there was definitely a strong community surrounding Apple’s developer tools long before Swift, there’s no denying that the introduction of Swift drastically transformed and shifted that community’s focus.
It’s astonishing how the language became such a major focus for Apple, and for the community from 2015 on when it became open source. The evolution increased exponentially and everyone benefits from it. It’s not by accident that Apple advertises a lot about learning this programming language, specially kids.
When I started to develop in Swift in 2014, it was on its earliest versions. It was very raw but still I got to publish an app in the store in about one week. Now the language is more mature, of course, and yet keeps its simplicity and robustness.