It still does, by adding yet another layer, written in a memory safe language.
Just like a castle with a water pit can still be conquered, but it takes a bit more effort for achieving it.
I do not care about memory safety only, I would be pissed if it removed my files, for example. :D Security is too broad a term anyways, hence this thread.
Depends entirely on threat model. More code is more surface area for vulnerabilities to be found.