One example where Rust enables better and faster abstractions is traits. C you can do this with some ugly methods like macros and such but in Rust it’s not the implementers choice it’s the callers choice whether to use dynamic dispatch (function pointer table in C) or static dispatch (direct function calls!)

In c the caller isn’t choosing typically. The author of some library or api decides this for you.

This turns out to be fairly significant in something like an embedded context where function pointers kill icache and rob cycles jumping through hoops. Say you want to bit bang a bus protocol using GPIO, in C with function pointers this adds maybe non trivial overhead and your abstraction is no longer (never was) free. Traits let the caller decide to monomorphize that code and get effectively register reads and writes inlined while still having an abstract interface to GPIO. This is excellent!