Of course at the end of the day it's just marketing and doesn't necessarily mean anything. In my experience the average piece of Rust software does seem to be of higher quality though..
There are no exceptions. There are no nulls. You're encouraged to return explicit errors. No weird error flags or booleans or unexpected ways of handling abnormal behaviors. It's all standardized. Then the language syntax makes it easy to handle and super ergonomic and pleasurable. It's nice to handle errors in Rust. Fully first class.
Result<T,E>, Option<T>, match, if let, if let Ok, if let Some, while let, `?`, map, map_err, ok_or, ok_or_else, etc. etc. It's all super ergonomic. The language makes this one of its chief concerns, and writing idiomatic Rust encourages you to handle errors smartly.
Because errors were so well thought out, you write fewer bugs.
Finally, the way the language makes you manage scope, it's almost impossible to write complicated nesting or difficult to follow logic. Hard to describe this one unless you have experience writing Rust, but it's a big contributor to high quality code.
Rust code is highly readable and easy to reason about (once you learn the syntax). There are no surprises with Rust. It's written simply and straightforwardly and does what it says on the tin.
Memory safety doesn't only have security implications, but reduces crashes, misbehavior and corrupt data.
You don't want either in any software, which has to fulfill a task in a productive way.
I would much rather try and figure out a bug in unfamiliar rust than in unfamiliar cpp.
2. Rust doesn't have memory management like in C. In Rust, abstractions and the compiler manage memory for you, except when you opt into C-like memory management using unsafe.
3. The comment was about memory safety, not memory management, and its benefit.
4. In case of GC vs manual memory management was used as a speed comparison: You might not REALLY need the speed of Rust, but I gladly take it where I can. I am tired of sluggish resource hogging electron apps and similar. Electron probably destroyed at least 10-15 years of progress in hardware performance gains.