Note that a subroutine doesn't return an array, but rather a list. That can make a lot of difference. Consider this code:

use 5.010;
{
   my @a = (1, 2, 3);
   sub a {
       return @a;
   }
}

my @x = a();
push @x, 4;
say a();
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If perl returned by reference (as you seem to suggest), this would print 1234, now it prints 123.

You can't have everything and a pony...