C did a ton of things right, but it also did a ton of things wrong. Learning from that and moving on would be the sensible thing to do after 50 years.
You're really exaggerating the problems. Does your negative opinion of C come from experience, or did you listen to the Rust evangelists who have an incentive to make the difficulty appear bigger than it is? Because it hasn't been my experience that C is this huge minefield of bugs that are impossible to explain or debug. You prevent a lot of bugs by actually understanding the language instead of coding by trial-and-error, the remaining bugs usually get caught quickly if you use an advanced compiler like GCC or Clang with the right flags (warnings and sanitizers), and for the occasional bug that slips through, the debugger tends to be helpful.
It's true that C has a bunch of historical footguns like gets and strcpy that you need to avoid. It's a very bad language to learn by trying random things and seeing what works. However, it's possible for a "mere mortal" to write good code. You just need to do more up-front learning than you could get away with in e.g. Python. If you pick a good book and listen to experienced programmers, they will tell you what to do and what to avoid.
And regarding abstraction—you can go very far with just structs and pointers, but you have to do things the C way rather than trying to write Java in C. If it's enough for Linux devs and their millions of lines of code, it will be enough for your personal microcontroller projects.
There is a very promising contender in the low level space that aims to fix some of C's problems, it's a new language called Zig. However, it's at a pretty early stage; even if it catches on, it will be many years from now. Right now, if you want to do low level work, you'll benefit from becoming good at C.
Zig looks perfect so far, but it's too early to switch over yet.
Any other promising candidates?
Even just requiring users to integrate my hypophetical Ada library source distribution into their project's build system files would most likely drown me in support tickets ;)
Or D itself if you don't need a language as minimal as C. D is basically C++ redesigned and now that GCC includes D support by default I wonder whether it'll gain popularity.
PS: my main use of C is currently to write platform abstraction libraries with minimal size and runtime overhead, so need to talk directly to operating system APIs, plus WASM is a very important target. The libraries must be usable from other languages via automatic bindings generation (quite simple with a C API). Also for performance-oriented stuff, direct control over memory layout and lifetimes please.
Also personal opinion from 20 years of C++ experience: high level abstractions never pay off in the long run. Simple imperative code always wins when it comes to "malleability".