> I think the appeal of C is that you are able to write the fastest implementation any given algorithm, something that just isn't possible in most other languages.

Maybe you can, but lots of the C code I've seen in the last years was pretty inefficient compared to what one would have gotten from a reasonable C++ or Rust implementation:

Examples are inefficient strlen() operations due to the default "string" type, unnecessary copies and allocations of things like strings due to ambiguous ownership, unnecessary null checks to quiet down static analyzers in the absence of non-null references, and extra indirections or allocations in order to work-around missing compile-time generics (besides macros), etc.

> I think the appeal of C is that you are able to write the fastest implementation any given algorithm, something that just isn't possible in most other languages.

If you told this out loud during the 80's and early 90's everyone would just laugh.

True, and I meant this in the context where you could embed assembly into your functions if needed.

That's not a very satisfying answer, as it doesn't apply to the languages typically compared with C- C++, Rust, or even D, Nim, Zig, etc.

I don't think struct + function is any more OO than tuple + lambda is. That's a very shallow definition of OO.