It is different yes, having read a good amount of it by now I find it work's pretty well in practice. It means you can incrementally adopt them if you like and code with or without them looks quite similar assuming you documented your code, the function signatures look the same as well which I appreciate.
C3 benefits from focusing more on the problem at hand than language complexities.
There are definitely advantages to simpler tools, you can streamline development and make people more productive quicker. Compare that scenario to C++ where you first have to agree the features you're allowing and then have to police that subset throughout on every PR.
Community support in C3 is massive, as you can use C libraries directly, it might parallel or exceed Rust on that metric, and the barrier to adding native C3 wrappers or versions is significantly lower too.
Rust is solving a different problem, that of safety over all else.
C3 on the other hand is more akin to developer experience above all else.
If you find something that should be easier to do in C3, that's a bug.
Unfortunately those things often come down to a chicken and egg scenario. Popular things get more popular, because they have demand, people write articles and then people visit the repo, write books etc they are strongly linked.