> I assert there is no reason to rewrite LLVM in Rust.
Everybody agrees with that, though? Including the people writing rustc.
There's a space for a different thing that does codegen differently (e.g. Cranelift), but that's neither here nor there.
> And I also assert that the speech that Rust is going to take over the C++, misses on that as long as Rust depends on LLVM for its existence.
There's a huge difference between "Rust depends on LLVM because you couldn't write LLVM in Rust [so we still need C++]" and then "Rust depends on LLVM because LLVM is pretty good". The former is false, the latter is true. Rust is perfectly suited for writing LLVM's eventual replacement, but that's a massive undertaking with very little real value right now.
Rust is young and arguably incomplete for certain use cases, and it'll take a while to mature enough too meet all use cases of C++, but that will happen long before very large institutions are also able to migrate their very large C++ code bases and expertise. This is a multi-decade process.