I have been using Rust extensively for over 2 years.

In those two years, the language complexity has increased substantially. It's already at a stage where I'm worried about losing track.

Also, there is quite a large amount of changes in the pipeline that were already accepted but are either not finished or not implemented yet. All of those can/will have a significant impact on idiomatic code and API design and will increase the complexity burden:

* specialization * generic associated types (a simple form of higher kinded types) * async/await + generators * existential types * const generics ...

So I do believe Rust needs to slow down considerably and get much stricter with accepting new features. Both to not overwhelm the existing userbase and to not make the language another C++ in terms of complexity.

And while I think Rust could do just fine without GATs, specialization is something I'd really hope for.

People will never be satisfied though and always ask for new features.

So I don't agree that the age of "The age of multi-vendored languages like C or C++ for systems programming might be coming to an end.", unless you mean we will managed to get rid of all OSes written in them, specially UNIX flavours or GPGPU libraries.

It would be nice, but it won't happen until the next big hardware revolution like Quantic computers being developed in Q# for example.

That's because you can't make money writing compilers anymore.

I thought that sqeezing MIR in the middle Rust could get both Rust-specific transformations and then benefits from the LLVM generic code optimizations...

LLVM is fantastic, but it's also a huge C++ component, and it's not necessarily optimized for speed. It would be nice to end up with something in Rust to simplify the toolchain needed, and to maybe have something that could be even faster for debug builds.