All things considered the way they’re approaching the migration is fine enough - they’re only moving specific portions at a time, they’re not stopping C++ development, and they’re making sure it doesn’t introduce regressions. Adopting a memory-safe language for something like a browser makes sense because it completely eliminates that class of vulnerabilities.

The problem is the way they’re approaching the code itself. From their wording, it sounds like they’re relying on AI heavily for both writing and reviewing the code. Rust has a steeper learning curve than most languages and is very different from C++. They even mention in the blog that their current Rust code looks like C++ code ported over. If they don’t take the time to actually learn Rust before adopting it, it’ll just lead to security logic issues that their AI couldn’t catch because C++ and Rust don’t always behave the same way. And that’s completely ignoring all of the other ethical/technical issues with AI