I'm fascinated by C. I agree that using almost anything else automatically eliminates entire classes of bugs and vulnerabilities, but it's so much _fun_ to be close to the machine and avoid those bugs and vulnerabilities myself. Judging by the fact that even some greenfield projects are still written in C, I'm not alone.
I am as much of a rust shill as you'll ever meet, but I agree that there is something beautiful and alluring and simple and engaging about C that few other languages match. It's basically an advanced macro assembler for an abstract machine, so there's all of the allure of using 6502 or 68000 assembly language but with none of the portability problems, and a vast ecosystem of libraries and amazing books to back it up.
I've enjoyed writing a few projects in x86-64 assembly as well, for what it's worth. Even though I'm sure that any C compiler would generate better assembly than my handwritten one. Flat assembler is great, by the way.
Any C compiler can generate better assembly for a function. But there's often some whole program optimizations that you can make, which the C compiler isn't allowed to do (because of the ABI/linker).
For example, a Forth interpreter can thread its way through "words" (its subroutines) with the top-of-stack element in a dedicated register. This simplifies many of the core words; for example, "DUP" becomes a single x86 push instruction, instead of having to load the value from the stack first. And the "NEXT" snippet which drives the threaded execution can be inlined in every core word. And so on.
You can write a Forth interpreter loop in C (I have), and it can be clever. But a C compiler can't optimize it to the hilt. Of course it may not be necessary, and the actual solution is to design your interpreted language such that it benefits from decades of C compiler optimizations, but nevertheless, there are many things that can be radically streamlined if you sympathize with the hardware platform.
