You're comparing apples and oranges. They have very different styles and strengths.
Lulu is a good mix of utility support, mage and pitch-hitting ADC. She has basically everything you want from a support, and has an amazing poke in the early game, but she melts quickly in the face of damage.
Leona is a highly durable shock trooper with hard crowd control out the wazoo, but she has no poke and no direct utility with her companion outside of items and her passive, and her range is meant for initiating and committing to a fight, not for poking (harass and provoke) or artillery (damage with the intention to maim or kill).
Don't pay attention to the meta. Slit its throat and throw the gurgling corpse overboard. Supports are a tool to be used in specific situations you find appropriate.