I think you're missing the point. The point is that you can get all those properties in Rust without the performance hit. (Except for, well, GC, obviously)
Stop using serde. please.
And on top of that iteration time is hurt because of both the language, the compiler perf, and the lifetime problems that you need to constantly think about
The benefits of using rust on other hand is non-negligible, i wish the team would focus on solving that kind of immediate problems