As much as I like Rust,
> In this context (where you don't plan on publishing you stuff on crates.io) a “crate” are just a directory at the root of your repo, the ergonomic impact is literally zero.
Is not true, you can't have circular out of crate dependencies. This often means you now need a third crate that's a trait crate, but then you can't implement external traits on external types, so you need bridge crates, and so on.
Rust's limitation of performance requiring lots of crates indeed has real impacts on projects beyond simple hello worlds or trivial cli apps.
Considering it to be a zero impact issue is rather reductive, even in the context of the language's design principles itself.
Rust for all it's good sides has had a lack of interest from core team and energy to drive real valuable changes beyond the nightly blockers into stable, or maybe they are working real hard and the boulders are so hard to move that we can't see any change looking outside in.
Is it justified after the gargantuan effort that was merging Async and GATs? Yes.
But acknowledging the problem doesn't help us solve it.
This is to say, Rust is an amazing labour of love project that seems rather stuck in time due to lack of investment/time/effort or all of the above, I am not sure, but it's moving slower than I would like, at solving the problems Rust developers face everyday.
And yes Rust compiler is slow (very slow is arguable, compared to modern C++ it isn't that bad, but compared to say Go without cgo, its horrid), Cargo is just bad, without proper hermetic builds and stuff, even when I setup sccache for our team and our cache hit rate remained below 20% and most of it was just C++ deps hitting the cache.
Just to be clear Zig builds are quite slow too, especially on windows where debug builds also use llvm.
TBH Zig debug builds on Linux also don't really feel that fast, C still compiles faster for me by a considerable margin.
Either way as someone doing Rust everyday for last 8+ years, 5+ in small/large teams, I have lots of complaints and I am sad, it has been over years of me complaining without nearly enough progress, they have a survey declare ambitions, and then well... things just don't move much.. not nearly as much as I would have expected.
Honestly given I have been a rust dev for over half a decade now, I should instead of commenting here probably be figuring out if I can contribute to Rust to help things along (faster?).
But most meetings and discussions happen at very EU/US centric times, and number of non US/European core contributors in Rust is also rather small(I don't know of one but I hope there are a few) so as someone not in those circles, I don't have the energy to figure out my way in, with my day job.
Tldr; Is Rust the language for the job here, likely. But the question should be why couldn't have been the language Bun was written from the very start. Why does Zig or C++ or C seem so much more productive.
Sorry for ranting about this but this felt a little relevant since you claimed people complaining, are likely people who have never worked with Rust.