This is the right choice if you want the language to be "a better C" but it means that there is none of the Run-Time Type Information that we are used to in C# (or java).

The RTTI plays a small but key role in e.g. how a DI container works: The container works out what parameters a constructor needs at runtime and instantiates those recursively; and in how a mocking framework works: Generating a class on the fly with the right interface declaration. Even XUnit/NUnit work by using RTTI: The testing framework looks for all classes/methods with the right attribute metadata, and runs them.

It's easily fast enough for how we use C# and Java, but it's not zero-cost.

There are unit testing tools in Rust, but they cannot work the same way - IIRC, there is compiler support for them. So, While Rust as a good chance at being "A better C", don't expect it to do all the things that C# does involving types at runtime. A different goal meant a different language design.

There are other interesting things in Rust like the Macro system that might help do similar things, but it's really not going to work like in C#