HUD (interface) on/off (Grand Theft Auto 5)

I honestly don't understand what is stopping developers to make a button which will power on and off interface, I'm not only talking about this game, but about the whole situation.
Pressed the button and there is no interface, clicked again, and there, convenient and easy. For some games post these scripts so I would be glad if there will be something similar, or at least via config

Simple Trainer to help, there just is, other trainers, probably, too.

I go nuts from people who are just cons, it's just pzts