For desktop, server, web, mobile, etc. This holds true. Not so much for embedded systems, anything with unnatractive memory capacity or processor performance. Rust is starting to make it's way in, but C and even assembly is still king AFAIK.
Toy systems, yes. Hey, I too, think CircuitPython is really neat. But I'm skeptical someone would base a PLC (or similar) on it.
The James Webb Space Telescope runs JavaScript, apparently [1].
[1]: https://www.theverge.com/2022/8/18/23206110/james-webb-space...