Custom Games/Practice tool suggestion

So I use the practice tool and I also play custom games if Im about to go somewhere. I was wondering why you need internet connection aka Wi-fi still if im just playing by myself with AI's. Games like Cod have that option when you make a custom game with AI's you dont need internet for it. Sometimes its raining and the internet isn't great. Thats why I play custom games or practice tool so I wont get a leaverbuster if the wifi signal isn't strong enough to keep me connected to the game. Sometimes Im traveling with my laptop and I just want to play some custom games or use the practice tool to kill some time when there is no wifi available. So Riot is their a reason why you need connection when you're just playing with AI's? If possible you should implement this in the future aswell.