how come performance is worse than Rust? Isn’t this misleading
It's possible to hack Function to perform a direct call and avoid (most of) the overhead, but in 99.99% of use cases this won't matter cos most processing time will be spent in the body of the function, not the scaffolding that Function uses.
You don't have to take my word for it: you can pull the C++ source code that we generate from a given Python function and inspect it yourself: https://docs.fxn.ai/predictors/compiler#compiling-binaries