What if we changed damage to turrets?

Right now, mages deal 40% of their AP in damage to turrets when they auto-attack them. What if turret armor was buffed slightly and that 40% was buffed to 60% or so?

ADCs have been a mainstay of the meta for years due to their monopoly on objective control. But what if they no longer had that? If building AP allowed more objective control, ADCs would become less mandatory and might no longer be the core around which the meta has revolved for the past several years.

NOTE: I'm not advocating for or against this change. This is a thought experiment regarding destabilizing a core pillar of the meta.