I don't think it's fair to call Swift an OOP language. It is certainly multi-paradigm, but provides a lot of facilities for functional programming as well. If you are not working directly with Cocoa, you can do a lot of interesting stuff with structs and protocols.
It appeals to me as a server-side language, and I've never done any iOS work. The reasons it appeals:
- Static types
- Good type system
- Lots of good support for immutability
- Apple is heavily invested in Swift, and very responsive to the community
It has some downsides. I'd evaluate Swift against Clojure and Elixir (which both have good, though quite different, concurrency stories), and maybe Haskell (but that would be tough from a buy-in perspective). But evaluating it against Python (which my team currently uses), it's hard to see a downside; we chose Python for Django and DRF, but we're increasingly not in love with that choice.
