I'll challenge the premise, actually. I feel I spend less time in Rust writing the code the first place (including fixing borrow checker errors, etc) than I did in C++, since in C++ I needed to spend so much mental effort worrying about whether my references are ok, whether my pointers might be null, etc.
The comparison to C# (basically Java, but I'm more familiar with it) is less obvious; it depends greatly what you're doing. Much of the time one uses C# because they're fine spending some CPU and memory for more productivity, and that's great and appropriate. Seriously-perf-critical C# code, though, might not be easier then Rust -- manual arena management in C# to avoid GC costs is no fun, for example.