1 competent dps can take a healer out of an entire fight be it even through outright killing them or forcing them to heal themselves.
The only issue it when said healer is guarded or being chain healed but that's an extra person we got now so you're 1v2, where's your team?
a couple good dps can down a healer through guard easily. even having another healer healing the one you're hitting 2 dps can still take them down. People are forgetting if you and a buddy are hitting healer #1 and healer#2 is healing healer#1 that's two healers that aren't even healing their own team and if your team cannot kill anyone whilst they're occupied then something else is going horribly wrong anyway.
I play a vanguard.