Earlier quoted context omitted.
Have you tried C#? Sounds like it would fit your needs perfectly, additionally benefitting from a huge ecosystem behind it.
C# doesn't have algebraic data types and pattern matching though, right? I'm not the same person, but at least for me that's one of the big advantages of Rust, and it's one of those features that outside of Rust you only really find in ML-family languages. I know it's possible to simulate it partially using sealed classes in some languages, but that's always seemed like a lot of boilerplate in comparison.
C# can fake algebraic data types in some ways/some cases. Though if you are expecting to do a lot of it you are still better off in F# or C#/F# hybrid projects. (F# of course being a proper ML-family language.)