From Dave Verwer:
Competition in this area is a good thing, but with Xcode being so good and VS Code’s support for Swift getting better every day, it’s an extremely tough market to enter with a paid product.
I have to totally disagree on Xcode being “so good”, unless it’s improved a lot in the last couple of years. In terms of developer productivity the JetBrains tools that AppCode is based on were light-years ahead of Xcode. I find it difficult to believe they’ve caught up even now.