Why is ::operator new[] necessary when ::operator new is enough?

Question

As we know, the C++ standard defines two forms of global allocation functions:

void* operator new(size_t);
void* operator new[](size_t);

An

Answer 1

::operator new[] and ~delete[] facilitate memory usage debugging, being a central point to audit allocation and deallocation operations; you can then ensure the array form is used for both or neither.

There are also lots of plausible if highly unusual/crude tuning uses:

• allocate arrays from a separate pool, perhaps because that crucially improved average cache hits for small single-object dynamically-allocated objects,

• different memory access hints (ala madvise) for array/non-array data

All that's a bit weird and outside the day-to-day concerns of 99.999% of programmers, but why prevent it being possible?