To improve safety at large, Rust has to displace C++. People use C++ in part because of its speed (rightly or wrongly - but it is undeniably part of C++ culture

To improve safety at large, Rust has to displace C++. People use C++ in part because of its speed (rightly or wrongly - but it is undeniably part of C++ culture). A language which is consistently slower than C++ will not displace C++. So, this was a point where the designers decided to hold their nose for now.