I could be wrong, but I think the easiest way to think of this is to consider how much extra memory programs took when compiled with 64 bit pointers over 32 bit ones. Suddenly every pointer takes double the memory. Which, sure, isn't a huge deal if you don't have a lot of memory allocations. But, if you do, it can add up.
Places it would likely impact more than you'd realize is in higher level language arrays where each item in the array is a pointer. For similar reasons, many datastructures can be coded such that each "pointer" is an array index instead.
So, extending all of that, what if you could make your pointers even smaller than 32 bits? If you know the addressable need for where the pointer is used, there is no reason you can't go smaller.
Places it would likely impact more than you'd realize is in higher level language arrays where each item in the array is a pointer. For similar reasons, many datastructures can be coded such that each "pointer" is an array index instead.
So, extending all of that, what if you could make your pointers even smaller than 32 bits? If you know the addressable need for where the pointer is used, there is no reason you can't go smaller.