This argument can apply to every application scene of Rust: no need to learn a new language. Yet the fact is that the Rust community is growing rapidly, from audio to embedded devices. I think the key is how much you can get from the investment, and I totally understand if people want to stick to the ecosystem they are already familiar with, a completely different story compared with a beginner.

Also, I don't think the JUCE "rules in the audio industry". First, the most typical use case for JUCE is to write VST plugins. Second, the company ROLI was trying to develop another language called SOUL. Although its progress seems to stop now, it somehow shows that they are trying to provide something different from C++.

It is growing, it is like going through the C++ adoption as I did 30 years ago, and still there are domains it could never take over from C.

So while it is nice for the security of the IT stack, we also need to keep things in perspective.