If you're manually calling malloc in Rust, your code is almost certainly wrong. It might be called as an implementation detail when you create new objects, but std can generally be used as if it were managed automatically.
replyGC is such a mistake though, you don't have to use rust but to never have to think about memory is a disservice to the programmer. Because that is something you always should do, and if you do then GC is nothing but a hindrance.
replyFor scripting etc. it is perfect though.
Why does having. GC mean not thinking about memory? I think about memory constantly in GC languages because I still want it to perform well.
replyThe biggest difference is the failure modes. If I'm not thinking about memory, my RSS is higher or a bit of extra CPU time goes to GC. Both of those are radically better than UAF or buffer overruns. Good trade IMO.
For a lot of programming tasks, HAVING to think about memory is a disservice.
replyThat's part of the reason why Python, go, Ruby, etc. are so popular.
There is no one right answer, it's very dependent on what's being built and where the ROI for the programming effort comes from.