Not a magic bullet, but there's hell a lot of difference between maintaining C and Rust code.
In Rust it's much easier to create robust and performant abstractions that are near impossible to misuse, eliminating tons of potential bugs right away.
In Rust you don't need 10 years of experience and staring with a microscope and at every line to ensure it doesn't introduce issues. In Rust trivial changes and indeed trivial, so you have more time to think about actually difficult parts.
In Rust contributors don't need to learn custom implementation for collections, string and other basic primitives on every project.
And most of all, people actually want to learn and work with Rust, so your contributor pool is expanding, not shrinking.
In Rust it's much easier to create robust and performant abstractions that are near impossible to misuse, eliminating tons of potential bugs right away.
In Rust you don't need 10 years of experience and staring with a microscope and at every line to ensure it doesn't introduce issues. In Rust trivial changes and indeed trivial, so you have more time to think about actually difficult parts.
In Rust contributors don't need to learn custom implementation for collections, string and other basic primitives on every project.
And most of all, people actually want to learn and work with Rust, so your contributor pool is expanding, not shrinking.