Sure, Rust is better than C++ in some ways. You can have a legitimate debate about C++ versus Rust. There can be no debate about C versus C++: the latter is better in every single way.
> unnecessary excess of C++.
Is the unnecessary excess of C++ in the room with us right now?
Again, you don't have to use any part of C++ you don't like. A few minor spelling differences aside, it remains a superset of C. Using C++ not C will not hurt you in any project whatsoever.
C is simpler because you don't need to remove any of that stuff, because it's not there to begin with.
My argument about Lisp doesn't say that anyone should use Lisp instead, it just points out that people making the choice between C and C++ aren't concerned by how easy it is to build new languages using the language building tools of C or C++ because both are very bad at it. Had the objective of building a new language been the primary objective of such projects, they'd be using a language with superior language building tools (not necessarily Lisp, there are many alternatives, it's just that neither C nor C++ are good at it).
In other words, if you don't want the language runtime, if you don't want C++ templates, smart pointers, classes, lambdas, exceptions etc. But, you want to be able to manage memory for eg. realtime kind of system... simply removing all the unwanted stuff from C++ is harder than it is with C.
And, if you did want some / all of those features of C++, there are saner languages to have that (and you'd pay for it by having to drag in their runtime and conventions). Before Rust was a thing, I've seen people choose D instead, for example, as a kind of middle ground between the asceticism of C and unnecessary excess of C++.