ADCs should scale slower

You have bonus gold, indirect buffs to supports, a meta issue with ADCs being a major contributing factor to whether a team wins/loses, and a problem with towers being too weak. You have lethal tempo and PTA as well, all great runes. Triumph gives bonus gold and kelptomancy is beautiful. With all this bonus income, the ability to be in debt, and the amount of itemization advantage AD champs have with the fast pacing of games now - I would say a good WAY TO NERF ADCs is by increasing the price of zeal items by 500 gold each(additional dagger requirement with 200 gold added to the tier 3 item).

This solves a lot of issues. ADCs are more in line with their late-game/mid-game pinnacles. The scaling between mages and ADCs and Bruisers/Tanks are actually sensible. (If you didn't know, ADCs have the cheapest builds). The game will not be around ADCs for its early/early-mid portion. Top, jungle, and mid-lane will shine more. Buffs to support items won't cause ADCs to get out of control like with Ardent Censer early due to the farm requirement as well. (Crazy items like the old ardent may still be realy strong, but at least the ADC will scale at a later time period)

Just something to think about. Please note, there's a lot of changes with pre-season so this idea may not be too great. However, I do think it is something worthy to consider.