Earlier quoted context omitted.
I'd be hard pressed if a backend in Rust gives the same perf as Kotlin/F#. Especially if you write the Rust with an async stack you will likely come out significantly faster than the other options: small binaries, short startup time, less memory usage, more throughput, slightly shorter request cycles, ... The only place that the langs you mention probably win is: learning curve (F# maybe not so much) a.k.a. getting l…
You forgot development times.
> a.k.a. getting language illiterate people up to speed, and compile times.
With equally skilled people I dont think these languages yield different dev speed, apart from the damage done by compile times.