This is the most surprising comment to me. It’s that bad? I haven’t benchmarked it myself.

Zig has @Vector. This is a builtin, so it gets resolved at comptime. Is the problem with Rust here too much abstraction?

I think you misinterpreted GP; he's saying that with some hints (explicit chunking with a branch on the chunk size), the compiler's auto-vectorization can handle the rest, inferring SIMD instructions in a manner that's 'good enough'.