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.