I'm not convinced c without assembly is much better than Pascal or even Rust. Sure, you might not need a full assembly course (write a real, multi-user, bare-metal os in assembler using most of x86 16,32 and 64bit syntax) - but a C course mixed with assembly I think makes a lot of sense if the goal is to learn a bit about how computers get work done.
I mean, one should be able to look at the assembler output of hello.c and have an idea of what's going on. Without that level of understanding, I'm not convinced using C over many other languages gain you much. It's still a lot simpler than eg. c++, though.
I think it depends on what modern means. If modern means more or less the system architecture basics from the 80s that our current systems pretend to be, C is a pretty straightforward mapping; but if modern means Intel kaby lake/amd ryzen, there's a lot of things going on that C or even assembly don't really address.
I mean, one should be able to look at the assembler output of hello.c and have an idea of what's going on. Without that level of understanding, I'm not convinced using C over many other languages gain you much. It's still a lot simpler than eg. c++, though.
I'm thinking something like: http://pacman128.github.io/pcasm/ but rewritten from the ground up for x86_64.