Well, you tried to appeal to a common logic, and I appealed to even more common logic. If you arrange 3 apples on a table in an array, and ask anyone to take the 0th apple, they will be confused.
0-based is just a convention, not a law of the universe. Only using integer-type numbers to address array elements is too merely a convention of some programming languages. And note that no one suggests using non-integer numbers here, only numbers of non-integer type.
What does it mean to access the element at index π of an array?
What does it mean to access the 0th element of an array?
It is the 0-th element after the start of the array. 0-based indexing is very common in both mathematics and computer science.
Well, you tried to appeal to a common logic, and I appealed to even more common logic. If you arrange 3 apples on a table in an array, and ask anyone to take the 0th apple, they will be confused.
0-based is just a convention, not a law of the universe. Only using integer-type numbers to address array elements is too merely a convention of some programming languages. And note that no one suggests using non-integer numbers here, only numbers of non-integer type.