You're wrong because it's also incrementally replacing individual, high-risk components in Windows and Linux.
But even if you're not wrong, a major mission of Rust was to be a safer C/C++, and language tooling used to be dominated by those languages.
All the language tools that are being displaced by newer rust replacements were definitely not written in C/C++. They were/are written in the host language (js/java/python/php/ruby).
Which is striking right? Nobody went "Oh, I should write C++ to speed up my Python tool", or if they did we don't know about it because they're still trying to understand the six thousand lines of template spaghetti their compiler spat out due to a typo in one line of their code.