Rust is not a panacea. No programming language is perfect. There are drawbacks to using Rust.

Rust is a very large and complex language. The learning curve is steep. And it may take a long time to master the language.

Rust's development approach based on memory safety incurs a steep cost in terms of productivity. Rust is never used for quick prototyping. If you need to get a product out the door in the shortest possible time frame, Rust is the wrong language choice.

Rust's strict discipline and rigidity impede flexibility and adaptability. If a project's requirements change substantially, Rust is a millstone around your neck.

That said, under the right circumstances, Rust is a terrific language. Memory safety does eliminate a great source of software defects. But this is not the only consideration in software engineering.