Take a step back and consider why the support gives up farm for the ad carry. It's because most supports don't depend on farm to be useful (e.g. Janna ult, Blitz grab) and often scale worse than other champions, while the ad carry can exploit the multiplicative returns of AD/AS/crit/armor pen which means that for every gold you spend, your next will be even more efficient.

Now consider that Volibear actually needs some amount of items to be useful come mid/late and a Kog who builds Archangels is not exploiting the scaling of AD itemization at all.. I'd say you did the right thing by making sure you got farmed yourself.