Earlier quoted context omitted.
I'll bet there are some Rust build options they can tweak to get it way down...
Here are a couple of options if anyone is curious: https://github.com/johnthagen/min-sized-rust
FWIW, when rebuilding jless with some of the cargo tweaks mentioned here, as well as in https://www.collabora.com/news-and-blog/blog/2020/04/28/redu..., I managed to get the binary size down to 1.75MB. Better, but still huge.
Note that I did not use tweaks which require rust nightly, as I did not feel like installing it.