Rust also has a much steeper learning curve. I can onboard an average developer that's familiar with Typescript and have them be productive in C# in a week.
This one is more subjective, but I also think C# has a more mature and painless web stack.
I love both languages but for me they each fill a different role.
I think this just says that TypeScript and C# are more similar languages than either is to Rust, which I would agree with. Rust's learning curve is not steep at all if you're coming from C or C++.
C# also has a pretty steep learning curve if you have to care about the things where Rust excels, like correctness or maximum efficiency (which typically does not include web stuff). I would even say that Rust is the easiest language in which to approach that level of correctness and efficiency.