Maybe making 3-5 S-'s on a champion that youre level 6 with should grant you a level 7 coin? I've gotten 6 S-'s with Ekko going 9/1/2 and 17/2/8 and I only need one more S. I've gone support and ADC Ekko with my friends and it's impossible to get.
It's not that it should or shouldn't, it's just that's the way it is. There aren't any pros/cons or balance issues to make it easier because it affects all players similarly.
It's just an extra aesthetic thing... no advantage to having one, doesn't mean you're a phenomenal player... really no point in making it easier or harder to get. But since you want it so bad, some others must too, so why not make it hard to get... otherwise everyone has one and it's even less meaningful than it already is. Just my opinion on it.
