"Artificial microbenchmarks" are very useful if there's a good chance the code might be called a few thousand times in a loop. If you write generic code that may get used by thousands or even millions of applications then these small differences do matter, and add up.

Also I think a lot of code will be needless awkward too; sometimes I really just want to get the first or second or last index. I don't want or need to iterate: I just want exactly nth entry, nothing more, nothing less. Yes, you need to be careful with it, but entirely removing them is not much of a solution.

I'll be sure to let my artificial users know that.

Like, my god man, next time just come out and say, "I do not consider your work or the use cases you care about valid, and thus I am going to dismiss everything you say on that basis." At least be honest.

There's a lot more stuff out there besides grep tools that need to go as fast as possible. I'm glad Rust exists for that and I'm glad its design is full of practical trade offs that people like you don't seem to see as reasonable.