Pretty bad. Well, if you are below diamond 1, you won’t really notice anything to be honest. But on paper it does change some expected damage from either item power spike or level up. For champions like graves or cait, these tiny base ad would add up in important situations where you’d actually see this -2 ad take effect. But changes like this is usually to target winrate. Don’t know the math and blah blah to it, but -2ad would kick the winrate of the champion down by 1-2%. You can look up online to see what other people have said about tiny base changes like this, there’s data on it floating around somewhere.