The above post tells us that any Selenium-base test script can not click the <input type="file"> element at all. That’s a correct behaviour as the W3C Specification defines.
Wow, here comes a Monster! I have never seen it. But I can guess a reason why.
If a browser opens a FileChooser dialogue when I click the <input type="file"> element using WebDriver, then how can I continue interacting with the dialog? — Nothing I can do. I can not interact with the OS-built-in FileChoose dialogue with WebDriver (=Katalon Studio) at all. Therefore I do not want the dialogue to open. Rather I want to send a file path to upload, and immediately go ahead.
It was a good learning. Thank you.