Keeping it simple to write a compiler is not a serious use case these days. People aren't bootstrapping new platforms from scratch. GCC and Clang are anything but simple.
Even if they aren't, people absolutely should be able to bootstrap new platforms from scratch. It's important to have confidence in our tools, in our ability to rebuild from scratch, and to be safe against the "trusting trust" attack among other things.
Lately I've been catching up on the state of the art in bootstrapping. Check out the live-bootstrap project. stage0 starts with a seed "compiler" of a couple hundred bytes that basically turns hex codes into bytes while stripping comments. A series of such text files per architecture work their way up to a full macro assembler, which is then used to write a mostly architecture-independent minimal C compiler, which then builds a larger compiler written in this subset of C. This then bootstraps a Scheme in which a full C compiler (mescc) is written, which then builds TinyCC, which then builds GCC 4, which works its way up to modern GCC for C++... It's a fascinating read:
There are multiple standards for C. C23 does not replace C17, or C11, or C99, or even C89. Maybe something should replace C89, but that's another discussion. I'd vote for C99 as a minimum target and prefer C11.
Just as you yourself described, one can absolutely target a platform from scratch with C99, Forth, Lua, a Pascal, a modernish Basic dialect, or some form of Lisp without building the largest, most modern compiler first. Once you have a compiler or even an interpreter for any of those, one can use it to create a compiler for something bigger and more modern. In fact, that's precisely where C was originally targeted - as a portable bootstrap language to various hardware platforms.
On the other hand, one can also target a new platform via LLVM. Both options have their merits and drawbacks.
Lisp and Scheme seem to discourage this sort of thinking in a great many programmers. After all, Lisps often start as just the eval function for their S-expressions and grow from there.
