May I ask what the nature of the Rust apps you're porting is? I'm currently learning Rust and would be interested in knowing why you're moving away from it.
Rust is probably more mature (more users) but requires me learning a lot of low level concepts. If you already know Python and just want fast code and easy deployment, Nim might be a better choice. Crystal is similar for Ruby users.
Since you self-describe as "coming from Python," you maybe haven't yet really gotten that deep into the internals of computers and what kind of stuff you might wanna do that isn't well supported by higher-level languages. This is especially relevant when we get to talking about performance guarantees, wherein very little can get "guaranteed" about a garbage-collected system, by definition. So while it is a pain to deal with "low-level concepts" like in Rust, it is also well worth it depending on what kind of tech you need to make.
With that being said, my day job isn't programming, but engineering which involves a lot of managing data so scripting languages are very vital: Python, Perl, R, Bash, Powershell...etc. Also, other technology like SQL and Excel are daily drivers.
I've used Java & C# a bit in the past which are fast languages, but they're missing the majority of linear algebra and optimization libraries that are widely available in Python/Matlab/Julia.
So what if one of my simulations is too slow for comfort? Re-writing Python in Julia or Nim isn't too hard (syntax is very similar) and i get a huge speed boost. That's all I'm saying. I'm being pragmatic about the situation. Of course I can rewrite performance critical code in C/C++/Fortran/Ada/Rust, but that is a huge last resort as those languages (well Fortran isn't as bad as they say) take me much longer to get something going and you're absolutely correct that my hardware understanding has greatly atrophied since college. For an engineer (in this case a traditional engineer and not a software engineer), we generally need code to A.) automate processes B.) design and run simulations C.) do data analysis.
We rarely write low-level software to twiddle bits unless we really have to. There are simply better choices to make the things I care about run faster even if I was good at C.
Random benchmark with the latest release. I don't know how reliable it is but in my experience Nim can often be very fast:
I have a group of related cli apps that need to do a lot of work while also polling swaths of the filesystem. In Python it would have been much, much too slow without C extensions, so I wrote them in Rust instead.
There's nothing wrong with Rust, it's a fine language! But ultimately, while ownership is a clever way to do memory, I personally prefer the sheer convenience of garbage collection when I'm trying to write something that's good enough, quickly. Nim is perfect for that!