nobody cared to teach the new devs, memory safety and the devs didn’t care to learn it themselves even as they became senior devs.
It does not matter how much you teach, humans are not perfect. The industry changes all the time, everyone updates libraries, systems change, editing others code is not as easy to understand, and so on. There is a reason why Microsoft, Google and Linux have experts in their fields for decades and yet these mistakes happen.
And it makes sense why using Rust would reduce memory vulnerabilities. Because the language has features in place to either prevent or make those mistakes more difficult to happen. If you understand what Rust offers, then its not science to understand why. Google is not the first and only big company reporting this either.