I agree about Rust's memory safety advantage over C++, but I disagree that it's disappointing from a project perspective. Some DB experts made a good DB using a performant language they're comfortable with.

You can't make project choices in a vacuum, and you can't assume others can either. People have limited time. The choice they were facing was probably not C++ vs Rust, but C++ vs nothing because they didn't have time to learn a new language before starting their project.

Also, their first release was in 2019, so they probably heard of it, but that's around the beginning of its recent spike in popularity. It's starting to be viewed as a good long term option, but back then a lot of people were still wondering if it was a fad.

I'm learning Rust, and I'm a big fan, but this is a bad take.