I still think Rocket is the most concise web framework for Rust after 5 years now of using it in projects and even newer frameworks, and also is one of the best examples of how ergonomic you can make frameworks and DSLs in-general using Rust's type system.
For those wondering what makes it so different, the "batteries included" approach really differentiates it from other web frameworks in Rust, and it reduces the total amount of boilerplate you need to setup for simple middleware, streams, and security just about everything you need to do for simple web services.