> Rust has macros that make serde very convenient, which Gleam doesn't have.

To be fair, Rust's proc macros are only locally optimal:

While they're great to use, they're only okay to program.

Your proc-macro needs to live in another crate, and writing proc macros is difficult.

Compare this to dependently typed languages og Zig's comptime: It should be easier to make derive(Serialize, Deserialize) as compile-time features inside the host language.

When Gleam doesn't have Rust's derivation, it leaves for a future where this is solved even better.