Even if Rust were as complicated as C++, with its ridiculous number of interacting features and backwards compatibility constraints, it manifests very differently: the Rust compiler keeps track of the complexity and tells you when things go wrong, while the programmer has to do pretty much all of this manually in C++. Many of the constraints Rust requires are constraints that people often try to do manually in C++ (e.g. avoiding dangling references and use-after-move), hoping that they get it correct.
My opinion is that Rust is at least as complicated as C++. They have different complexities, but one isn't "easier" than the other. I enjoy Rust a lot. More than C++, at this point, but that may be the "newness" factor creating bias. I think Rust is likely a better language for people new to systems programming to pick up. It's complexities are largely up-front: a novice will learn how to program well in Rust by having the compiler break his teeth a few times, while for C++ she'd either have to have high-quality mentoring or else learn the hard way (by long experience).