Back when I mained Lulu in League oh say roughly a decade ago, they were fun to play because their shield could also be used as an attack that set you up for an easy slow. Paired with the right teammate, that combo did in many an enemy AC. I also enjoyed getting a bunch of items with cooldowns that did things like speed us up for chases or add temporary shields, and an ult that - used right - temporarily interrupted and stunned the enemy in addition to adding some health.

Those kinds of dynamics, where you're buffing your team at the right time to secure kills in addition to healing them, made being designated support my preferred role.