In what scenarios would using array_diff in PHP be more beneficial than manually comparing variables in an array?

Using array_diff in PHP can be more beneficial than manually comparing variables in an array when you need to find the difference between two arrays. It saves time and effort by providing a built-in function that efficiently compares the values of two arrays and returns the differences. This can be particularly useful when dealing with large arrays or when you need to perform this operation frequently.

```php
$array1 = [1, 2, 3, 4, 5];
$array2 = [3, 4, 5, 6, 7];

$diff = array_diff($array1, $array2);

print_r($diff);
```

This code snippet compares the values in $array1 with $array2 and returns an array containing the values that are present in $array1 but not in $array2.