I'd agree it's largely the human factor, but maybe from a different angle. Rust has got the "there's a crate for that" factor, like JavaScript, which helps onboard people who are afraid of getting stuck writing everything from scratch.

For example, serde (and serde_json, toml, etc.) is a gamechanger, as is tracing, reqwest, and many others.

So, maybe less about the language itself for many people, but more about the human factor of overcoming fear of being stuck on an island