There are many simpler languages with speed and memory efficiency (Nim, Crystal and the like). Rust somehow became even more complex than C++; what an achievement (not).
Two things that might help Rust a lot despite the complexity are the tooling and the ecosystem. Cargo is good, the compiler is extremely helpful, and there are a lot of crates to build on for all sorts of tasks.
For example, if I need to use simulated annealing to solve an optimization problem, there already exist libraries that implement that algorithm well.[1] Unfortunately, the Haskell library for this seems to be unmaintained[2] and so does the OCaml library that I can find.[3] Similarly, Agda, Idris, and Lean 4 all seem like great languages. But not having libraries for one's tasks is a big obstacle to adoption.
Nim looks very promising. (Surprisingly so to me.) Hopefully they will succeed at gaining wider recognition and growing a healthy ecosystem.
Good to know that hmatrix-gsl works too. In this case, I went down the Rust route instead of the Haskell one. I use Haskell too, just not for simulated annealing.
My main domain is scientific computing and I get nervous about the prospect of not being able to run my code 5 or 10 years down the road (somewhat above the typical lifespan of a project that ends up published in my discipline). GHC gets updates that sometimes require library maintainers to update their libraries. Here is a list of a few:
