Trinkets should have replaced sightstone
Sightstone only exists because it was introduced at a time when supports could still buy green wards. It is a replacement for green wards.
In the current game, trinkets have replaced green wards, and therefore, sightstone could easily be removed from the game if the trinkets were balanced around that. Actually, when trinkets were first introduced, many people were ignoring sightstone because yellow trinket was enough vision. Instead of playing into that natural evolution of the vision game, Riot nerfed yellow trinket. I still don't know why.
I think that if yellow trinket were buffed again, vision could become a true team objective. Obviously, some other balance would need to be done around the lack of sightstone (likely changes to the three gold gen/sightstone upgrades), but I truly think that would be healthier for support and healthier for the game.
Since there is so much discussion about the support position and all, I thought this might be a good time to revisit this discussion. Thoughts?