Fair point. If you want to hack something together and don't care too much for the details, Rust will slow you down.

But if you care enough to be writing tests or put lots of thought into API and schema, then maybe you're in the disciplined camp that would get a ton of benefit from switching.

If you're using C++, you should switch for any greenfield project that doesn't need to use legacy libraries. (Writing wrappers for C libraries isn't hard at all.)