By the vague looks of it, he has tried Rust for something he would use C for. His impression of Rust's utility in that domain seems unsurprising.

Beyond that

I used to not question why we build anything other than "system software" in C/C++. Once I questioned that, I quickly got past the "Why not Ada/D/etc." stage and reached the "why is so much of large software written in mid-level languages" stage. For anything bigger than, say, a Unix CLI tool, it probably is, and has always been, wrong to use anything at the level of C (C++, Ada, D, Nim, Rust, Zig, etc.).

This choice of language level for "application software" seems to be a commercial choice. The software commons is using such languages probably because contributors want to hone their job-oriented skills. It got better with Python and Ruby uptake in open projects. But, efficient, safe but simple languages, say, OCaml and Erlang, have been available for decades. Crystal is also looking good right now.