C was great... for the PDP-11.
Nowadays, not so much. Computers are multiple orders of magnitude faster, have multiple orders of magnitude more memory and storage and do things multiple orders of magnitude more complex than they used to. Portable assembly still has its uses obviously, but safer/easier/faster alternatives exist in all its niches.
> Portable assembly still has its uses obviously
C is much closer to any other high level language than it is to assembly. 'Portable assembly' might have been true with trivial C compilers of the 70s and 80s, but not with compilers like gcc or clang.
> Computers are multiple orders of magnitude faster, have multiple orders of magnitude more memory and storage
And C is still the best way to talk to the hardware in a portable way.