You can "have your cake and eat it too" in Rust, C#, and I suppose C++ if you're a masochist.
These modern languages have both easy-to-use "owning" string types and a "string slice" type that can be passed around efficiently. Unlike C, in these languages a string and a slice are largely interchangeable, which makes them easier to use throughout not just your own codebase, but third-party libraries too.
For example, the Rust `httparse` crate `Request` type returns parsed fields as string slices, not strings, which means it doesn't allocate anything on the heap: https://docs.rs/httparse/latest/httparse/struct.Request.html