A heal over time thingy doesn’t mean that it’s going to require briggite’s attention. She can send the repair back to that zenyatta getting dived while still doing her thing in the mean time. It doesn’t mean she has to keep the button pressed or something.
Imagine a zenyatta orb that heals 60hps that goes away after a certain amount of healing (something like 200) is done.
Brigitte is supposed to be a support that peels for other supports not a one man army that can completely shut down 3 dive heroes on her own.