I do great when I play Uther, in fact he is my primary healer in QM. Uther excels because he has the best support abilities - burst heal, cleanse, holy shield, and armor. Yes he will provide less overall healing, but that is the case for every healer outside of Alex because of her insane healing potential.
My Uther heals will always be below an enemy Lili, Morales, Whitemane, or Alex, but the support abilities I can contribute during teamfight situations I believe make up for it.