Tier 3 & 4 Turrets Damage

Wondering what would happen to game mechanics if tier 3 & 4 turrets did percent health damage to champions, and temporarily stopped all health regen. The point of a turret is lost to me when Mundo can regain health under a tier 3 turret faster than it does damage. Shouldn't there be more strategy than simply being the tankier team? By 30-35 minutes your base turrets have become useless.