It's really not true that "every killer feature of Rust and Lisp is already in C#" although it's certainly true that C# is a nicer language today than it was twenty years ago.
Sum types are a must-have for me. I don't want to write software without sum types. In C# you can add third party libraries to mostly simulate sum types, or you can choose a style where you avoid some of the worst pitfalls from only having product types and a simple enumeration, but either is a poor shadow to Rust having them as a core language feature.
Also VS is a sprawling beast, I spend almost as much time in the search function of Visual Studio finding where a solution I've seen lives as I do hand solving a similar problem in Vim. I spend the time because in Vim the editor won't get in my way when I solve it by hand, while VS absolutely might "helpfully" insert unrelated nonsense as I type if I don't use the "proper" tools buried in page 4 of tab 6 of a panel of the Option->Config->Preferences->Options->More Options->Other section or whatever.
Visual Studio is what would happen if Microsoft asked 250 developers each for their best idea for a new VS feature and then did it, every year for the past several decades, without fail. No need for these features to work together or make sense as a coherent whole, they're new features so therefore the whole package is better, right? It's like a metaphor for bad engineering practice for every Windows programmer to see.
Use VSC instead. The higher-level alternative to Rust is more so F# than C# as it has comparably powerful type system with different tradeoffs (gradual typing and full type inference across function boundaries - it's less verbose to write than Rust because of this). Otherwise C# is not tied to VS at all because all the tools that it provides have alternatives either in Rider/JB suite and/or in a self-contained CLI way together with just using VS Code. .NET's CLI is very similar to Cargo in either case.
Sum types are a must-have for me. I don't want to write software without sum types. In C# you can add third party libraries to mostly simulate sum types, or you can choose a style where you avoid some of the worst pitfalls from only having product types and a simple enumeration, but either is a poor shadow to Rust having them as a core language feature.
Also VS is a sprawling beast, I spend almost as much time in the search function of Visual Studio finding where a solution I've seen lives as I do hand solving a similar problem in Vim. I spend the time because in Vim the editor won't get in my way when I solve it by hand, while VS absolutely might "helpfully" insert unrelated nonsense as I type if I don't use the "proper" tools buried in page 4 of tab 6 of a panel of the Option->Config->Preferences->Options->More Options->Other section or whatever.
Visual Studio is what would happen if Microsoft asked 250 developers each for their best idea for a new VS feature and then did it, every year for the past several decades, without fail. No need for these features to work together or make sense as a coherent whole, they're new features so therefore the whole package is better, right? It's like a metaphor for bad engineering practice for every Windows programmer to see.