Why the hidden test cases are not visible even after completing it

Answer 1

For an algorithm(steps in solving the problem ) to be correct, it must produce the same output for any given input.
If all test cases were shown it will simply make us write the code with respect to the inputs shown not considering other inputs.

Answer 2

If the test cases were to be unlocked, people could just cheat and make output based on the input, but not much coding.

Answer 3

No you can't see them they are permanently closed