I don't think anyone cares about Apple here. Swift solved a problem that people outside iOS/macOS didn't have. Then it took ~10 years to make Swift more seriously general purpose and multi-platform, it's simply too late to be compelling when other languages have progressed too.
Re: easy to write, I'm not sure, Swift's recent explosion in complexity makes it a hard sell vs Rust, even if the learning curve might be slightly less steep. At the end of the day, Rust's DX wins in almost every dimension, people are willing to learn slightly more complex semantics if it saves times everywhere else: tooling, libraries, build tool and package manager, ... I believe even compilation speeds don't compare favorably.
Re: easy to write, I'm not sure, Swift's recent explosion in complexity makes it a hard sell vs Rust, even if the learning curve might be slightly less steep. At the end of the day, Rust's DX wins in almost every dimension, people are willing to learn slightly more complex semantics if it saves times everywhere else: tooling, libraries, build tool and package manager, ... I believe even compilation speeds don't compare favorably.