I think it’s acceptable for Rust compilation to end up slower than C++. After all, the compiler does a lot more work for you with the borrow checker and all. That doesn’t mean we shouldn’t strive to make it better though.
One example to get you started, https://github.com/pjmlp/RaytracingWeekend-CPP
On the other hand, that extra time is traded off against not having to deal with bugs at runtime that the type system is able to catch. Rust is one of the better languages when it comes to making illegal states unrepresentable.
But he does specifically break down how much of compilation time is spent in the borrow checker, LLVM, macro expansion, etc.