Do Supports Need Items to be Useful?

(Coming from a Support Main) You often hear players say that supports should not take kills or CS, because the carries and the damage dealers need the gold more to get items. It's an understandable idea, since support items and tank items generally cost less than damage items, but what if you were to take the idea that supports don't need gold and items literally?

Recently, I've been experimenting by playing enchanter supports - mainly - where I buy before I stop building any more items and just buy Control Wards to get as much vision control as possible to compensate for my lack of utility items.

I'm only doing this in normal draft pick - not ranked - (on my own though) and have been having relative success both in the laning phase and mid/late game. I try my best and otherwise play like normal and don't troll (outside of obviously not buying items). If someone notices that I'm not buying items and calls me out for it, I will say that I'm 'testing the theory that supports don't need items to be useful' and immediately use the gold that I've accumulated to get items if they're not happy with what I'm doing.

I'm not suggesting that you should do this, but do you guys think that it's true to a certain extend to say that supports are still useful without items? I imagine that for tankier supports like , you probably do need tanky support items to be the tank, but with enchanters, where most of their power already built into their kit, is it feasible to use only your abilities and vision to support your team with this theory and fun little self-imposed challenge?

Again, I'm not saying that you shouldn't buy items as a support, but is there a degree of truth to the notion that supports don't need gold or items?