You're right, sort of. Because C doesn't have proper arrays, you make up for it by passing a pointer to the first element and the range. So for C to do as well as Fortran on matrix operations the compiler developers need help. One source of help is that if you have a pointer to double and a pointer to int, you can assume that writing pdouble[k] doesn't alter anything reachable as pint[m].

It's because C has pointers and FORTRAN doesn't and pointers are a pain for certain types of optimization.

Why would that put C at a disadvantage performance-wise? Array decay is, with hindsight, an unfortunate feature, but optimizing access to contiguous memory is very low-hanging fruit as far as compiler optimizations go.

Some optimizations are low-hanging fruit only if you know length of the array. Which C avoids by design at all costs.

If you want better safety, runtime and compile time performance the lowest hanging fruit would be to fire the C standards committee and hard fork C++/C into C++ and C only ecosystems.