Why is FormRequest in Laravel throwing a ValidationException instead of an array with errors?

Question

Laravel

Hello. There is, for example, a post route described in api.php. There is a regular controller and a regular FormRequest. I send json with Postman and if the fields are invalid, then instead of the "field => error" array, an exception is thrown

Illuminate\Validation\ValidationException
The given data was invalid.

Request

class CreateOrUpdateRequest extends FormRequest
{
    public function authorize()
    {
        return true;
    }

    public function rules()
    {
        return [
            'firstName'          => 'required|string|between:2,255',
            'lastName'           => 'required|string|between:2,255',
        ];
    }
}

Controller

class MyController extends Controller
{
    public function create(CreateOrUpdateRequest $request)
    {
        dd($request->all());
    }
}

Well, the result

Answer 1

https://laravel.com/api/5.7/Illuminate/Foundation/...
Add a failedValidation() method to the file to handle errors.
---
Maybe this article will help.

Answer 2

Because that's the way it's designed. This exception should be caught by the error handler and it will already generate the desired response - json or redirect. What did you write there that he does not do this - the question is for you.
Do you not read the documentation for ideological or religious reasons?