It doesn't make any difference which language you use; the security promises are coming from the verifier, which is analyzing the CFG of the compiled program. C is what most people use, since the underlying APIs are in C, and since the verifier is so limiting that most high-level constructions are off the table.

Sure, I was not implying that Rust would have any security benefits fir eBPF.

Just that you can even write eBPF code in more convenient languages.

This has come up here a bunch of times (we do a lot of work in Rust). I've been a little skeptical that Rust is a win here, for basically the reason I gave upthread: you can't really do much with Rust in eBPF, because the verifier won't let you; it seems to me like you'd be writing a dialect of Rust-shaped C. But we did a recent work sample challenge for Rust candidates that included an eBPF component, and a couple good submissions used Rust eBPF, so maybe I'm wrong about that.

I'm also biased because I love writing C code (I know, both viscerally and intellectually, that I should virtually never do so; eBPF is the one sane exception!)