According to that blog post (https://security.googleblog.com/2024/09/eliminating-memory-safety-vulnerabilities-Android.html https://security.googleblog.com/2024

According to that blog post (https://security.googleblog.com/2024/09/eliminating-memory-safety-vulnerabilities-Android.html https://security.googleblog.com/2024/09/eliminating-memory-s...), the vulnerability density for 5 year old code in Android is 7.4x lower than for new code. If Rust has a 5000 times lower vulnerability density, and if you imagine that 7.4x reduction to repeat itself every 5 years, you would have to "wait" (work on the code) for... about 21 years to get down to the same vulnerability density as new Rust code has. 21 years ago was 2004. Android (2008) didn't even exist yet.