Yeah, that's what I realized during this, too. You need to be much more explicit, but the way any given function works isn't fundamentally different. "strlen" will always iterate through a string searching for a NULL byte whether it's in C, Rust, Assembly, or whatever other language. I think it can feel almost more straightforward than other languages, since you're laying out exactly what the CPU needs to do, in what exact order.
Agreed. And super cool project. After seeing Matt Godbolts Advent of Compiler Optimisations in December I decided to do AoC in assembly. Was the most fun I had in years even though I didn't finish all days!
And super educational. Since then I've been pondering which problems require dropping down to the assembly level. E.g. implementing a JIT compiler, a coroutine runtime, etc.