C++ is a bloated mess that does exactly zero checking beyond type checking. Rust is a language that favors safety over build times and its serious users understand that.
Rust is also developed completely in the open. C++'s Standards committee is rife with resignation letters, accusations of misconduct, and walled gardens - not to mention years between standards updates, each costing a ton of money to even look at.
Yes, I understand. Rust has no standard. It has no stable ABI yet. Depending on who you are or what you're doing these may or may not be issues for you.
Alas, comparing these two as though one should outperform the other is nonsense to me. Of course Rust is slower than C++. C++ has had decades of maturity and has enjoyed many contributors to its tooling. Rust has not, and its feature set (as in, the things the compiler needs to do) is much broader than any C++ compiler is specified to do.
The end result here is this will only work to fuel more language wars and be used as a cheap weapon in further language debates. In my opinion, anyone who argued about which language is better than which other language has completely missed the point of computer science and programming.