Best part about maturity. It matures. I would jump ship in a heartbeat to Swift. I don't use it because I can't use it in most places, and I am slowly learning to choose what I become an expert in. It sure isn't everything.
But when I did use it, I loved it. I've written in quite a few languages, and it is my favorite, but not my go-to because of its limited environment.
I wouldn't. I don't like Swift's syntax. The ecosystem would likely not be mature enough either.