There were so many critical vulnerabilities attributed to that... and in spite of putting tons of measures this is still potential danger. I knew projects decided to use Java instead of C++ (which got array boundary checks) mostly to limit security surface.

Maybe if we could start CPU architecture from scratch, array with sizes would make more sense? Maybe even we could done it so memory segmentation would no longer be needed: https://en.wikipedia.org/wiki/X86_memory_segmentation

Haven't figured out the details, but maybe we can even gain some performance that way.