7.9 patch changes to Coin removed its uniqueness amongst support items.
While I like the general idea of making support interact in lane, I typically bought Coin on non-AP champions who did not move into melee range.
This change means I am wandering forward to get gold. This is exactly what Relic forces. Coin and Relic now occupy the same "gotta move into melee range" game play. There is still a difference between healing and mana, I suppose, but coin was really brilliant on champions who did not want AP but still wanted to stay back. It's Thresh-like now. Which is the entire problem. I always bought Coin on champions who were never as tanky as Thresh. Anyone that tanky, I would just get relic.
I don't know a great solution because, again, I like the idea of changing Coin to be more interactive. However, having two melee and one AP support items really just kills diversity in bot lane.