You don't need `guard` if your compiler disambiguates nils and assigns vars in if statements.
You don't need hundreds of hardcoded If<T1>, If<T1, T2> etc. types to support SwiftUI if your type system is actually designed to handle this. And you have proper expressions. And proper functions.
You don't need an awkward `some` keyword if your type system is designed properly.
You don't need callAsFunction because that's the compiler's job, not the programmer's. And can be replaced with any number of things, including (but not limited to) currying.
And the list just goes on.