To be fair I think Rust has very healthy selection of options for both, with Serde and Reqwest/Hyper being de-facto standard.
Rust has other challenges it needs to overcome but this isn't one.
I'd put Go behind both C#/F# and Rust in this area. It has spartan tooling in odd areas it's expected to be strong at like gRPC and the serialization story in Go is quite a bit more painful and bare bones compared to what you get out of System.Text.Json and Serde.
The difference is especially stark with Regex where Go ships with a slow engine (because it does not allow writing sufficiently fast code in this area at this moment) where-as both Rust and C# have top of the line implementations in each which beat every other engine save for Intel Hyperscan[0].
> (because it does not allow writing sufficiently fast code in this area at this moment)
I don't think that's why. Or at least, I don't think it's straight-forward to draw that conclusion yet. I don't see any reason why the lazy DFA in RE2 or the Rust regex crate couldn't be ported to Go[1] and dramatically speed things up. Indeed, it has been done[2], but it was never pushed over the finish line. My guess is it would make Go's regexp engine a fair bit more competitive in some cases. And aside from that, there's tons of literal optimizations that could still be done that don't really have much to do with Go the language.
Could a Go-written regexp engine be faster or nearly as fast because of the language? Probably not. But I think the "implementation quality" is a far bigger determinant in explaining the current gap.
Rust has other challenges it needs to overcome but this isn't one.
I'd put Go behind both C#/F# and Rust in this area. It has spartan tooling in odd areas it's expected to be strong at like gRPC and the serialization story in Go is quite a bit more painful and bare bones compared to what you get out of System.Text.Json and Serde.
The difference is especially stark with Regex where Go ships with a slow engine (because it does not allow writing sufficiently fast code in this area at this moment) where-as both Rust and C# have top of the line implementations in each which beat every other engine save for Intel Hyperscan[0].
[0]: https://github.com/BurntSushi/rebar?tab=readme-ov-file#summa... (note this is without .NET 9 or 10 preview updates)